Vehicle rearview mirror assembly incorporating a communication system

ABSTRACT

A vehicle communication and control system is provided that may be more readily installed in a vehicle and that utilizes minimal additional wiring. According to some of the disclosed embodiments, the electrical components of the “brick” of a communication and control system are integrated into a rearview mirror assembly. Preferably, the microwave antenna for the GPS and the cellular telephone antenna are also integrated into the rearview mirror assembly. Various functions and features of the system are also disclosed.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. patent application Ser. No.09/827,304 entitled VEHICLE REARVIEW MIRROR ASSEMBLY INCORPORATING ACOMMUNICATION SYSTEM, filed on Apr. 5, 2001, by Robert R. Turnbull etal. now U.S. Pat. No. 6,980,092, and claims priority under 35 U.S.C. §119(e) on U.S. Provisional Application No. 60/242,465 entitled VEHICLEREARVIEW MIRROR ASSEMBLY INCORPORATING A COMMUNICATION SYSTEM, filed onOct. 23, 2000, by Robert R. Turnbull et al.; U.S. ProvisionalApplication No. 60/216,297 entitled VEHICLE REARVIEW MIRROR ASSEMBLYINCORPORATING A COMMUNICATION SYSTEM, filed on Jul. 6, 2000, by RobertR. Turnbull et al.; and to U.S. Provisional Application No. 60/195,509entitled VEHICLE REARVIEW MIRROR ASSEMBLY INCORPORATING A COMMUNICATIONSYSTEM, filed on Apr. 6, 2000, by Robert R. Turnbull et al., the entiredisclosures of which are incorporated herein by reference.

BACKGROUND OF THE INVENTION

The present invention generally relates to a rearview mirror assemblyfor a vehicle and vehicle communication and control systems.

Vehicle communication and control systems are commercially availablethat provide a wide variety of communication and control functions. Anexample of such a system is the ONSTAR® system from General MotorsCorporation. Another example of such a system is disclosed in U.S. Pat.No. 6,028,537. Each of these systems includes a cellular telephone, avehicle position identification system (specifically GPS), a processor,and a connection to the vehicle bus. These interconnected elements notonly provide for conventional hands-free telephone operation, but alsoenable a number of other communication operations and remote vehiclecontrol functions. For example, such a system may automatically call9-1-1 and transmit the vehicle location (as provided by the GPS) whenthe vehicle air bags inflate, or enable a driver to request roadsideassistance or ask for navigational directions at the touch of a button.These systems also enable remote control of vehicle functions such asremote door locking or unlocking and reprogramming/personalization ofvehicle accessories. Additionally, such systems may provide for remotediagnostics of the vehicle. The systems may also allow for transmittaland reception of text/paging messages and enable the vehicle to betracked by the owner or the police.

The ONSTAR® system has been implemented by providing an electronicmodule, also known and referred to as a “brick,” which incorporates mostof the system electronics including the GPS receiver, the telephonecircuitry, and essentially all the electrical components for the systemexcept for the antennae in the vehicle trunk or under or behind theseats. The GPS microwave antenna is mounted elsewhere in the vehicle andconnected to the brick by a coaxial cable. The cellular telephoneantenna is typically mounted on a side window of the vehicle and isconnected to the telephone receiver by a coaxial cable. The userinterface, which includes the speaker, microphone, and pushbuttons, ismounted near the driver and hardwired to the brick. Additionally, thebrick must be wired to the vehicle battery and/or ignition. These typesof systems may also be connected to the vehicle bus (CAN, J1850, etc.),the door locks, the air bags, the vehicle radio, to any RS232, RS-422 orother serial communication ports, and to any diagnostic circuits. Allthis wiring makes the system difficult and expensive to implement. Whenoffered as a dealer-installed option, the wiring complexity of theONSTAR® system becomes even more of a problem.

Despite all the research that has been conducted and all the literaturethat has been generated relating to the use of position identificationsystems (GPS) in vehicular applications, little consideration had beengiven to the practicalities of where to mount the microwave antenna thatis to receive the microwave signals from the satellites. The ONSTAR®system has the microwave antenna mounted behind the front windshieldjust beneath the headliner or on the rear deck proximate the rearwindshield. This antenna mounting is described in U.S. Pat. No.5,959,581. Installing the antenna in this position is difficult.Published International Application No. WO 97/21127 discloses themounting of two separate microwave antennas in the two external rearviewmirror housings of the vehicle. While there are two microwave antennaslocated in the external rearview mirror housings, the system receivercircuit is located in the interior of the vehicle. The separation of thereceiver circuit from the antennas introduces significant manufacturingdifficulties. Coaxial cable typically used to connect the antenna to thereceiver is expensive and difficult to handle in a manufacturingprocess, since it cannot be kinked and is relatively difficult toterminate. Furthermore, such coaxial cable typically has relativelyexpensive push-on or screw-on type connectors that connect it to thesystem receiver circuit and/or microwave antenna. Additionally, vehiclemanufacturers have expressed an unwillingness to require their assemblyline workers to connect the components using such a coaxial connector.

While WO 97/21127 further suggests that the antenna could additionallybe positioned within an interior mirror of the vehicle, doing so is notpreferred because the interior mirror is movable with respect to thepassenger compartment, which may introduce error in the vehicle positionmeasurements. Also, it is better to manufacture because it puts all theelectronics in one housing and is more cost effective. However, it doesnot work as well. In general, GPS is a line of sight system. The moresky the antenna can “see,” the better the system will perform. Havingthe antenna mounted to the channel mount by the glass allows bettervisibility of the sky and hence performance. Also, it is desirable toreduce the variability inherent in the design. Having an antenna and itsradiation pattern changing as different people get in the car and adjustthe mirror is extremely undesirable. Further, WO 97/21127 additionallystates that metallic coatings on the vehicle windshield may interferewith the operation of a receiving antenna when mounted in an interiorrearview mirror assembly. Additionally, like the configuration where thereceiving antennas are mounted in the two exterior mirrors, the mountingof the receiving antenna in the interior rearview mirror housing alsopresents manufacturing problems associated with connecting the antennawith the receiver, which apparently is mounted in the vehicle instrumentpanel. In the ONSTAR® system, the GPS receiver is mounted in the brickwhich, in turn, is mounted in the vehicle trunk or under or behind oneof the seats.

As noted above, it is very difficult to install a vehicle communicationand control system in a vehicle. Furthermore, the next vehicle modelthis system is added to is likely to require a different installation.Tooling of parts for the vehicle may have to be modified to hold thebrick and the antennas. Space has to be allowed for all the wiringbetween the user interface, the vehicle, the audio system, the GPSantenna, the cellular antenna, and the brick. Each car may require aslightly different installation and have tooling modified and extraparts tooled to accommodate the system being added.

There exists the need for a vehicle communication and control systemthat may be more readily installed in a vehicle and that utilizesminimal added wiring.

SUMMARY OF THE INVENTION

One aspect of the present invention is to provide a vehiclecommunication and control system that may be more readily installed in avehicle and that utilizes minimal additional wiring. To achieve this andother aspects and advantages, the electrical components of the “brick”of a communication and control system are integrated into a rearviewmirror assembly. Preferably, the microwave antenna for the GPS and thecellular telephone antenna are also integrated into the rearview mirrorassembly. While it is preferable to integrate all the components of thesystem into the rearview mirror assembly in order to reduce the need torun additional wiring and to provide a system that is much easier toinstall, the present invention broadly is considered to be thecombination of any two or more of the following components integratedwithin a rearview mirror assembly: a microwave antenna, a microwavereceiver, a wireless communication device, such as a cellular telephoneand its antenna, a Bluetooth™ transceiver, a Bluetooth™ controller, aBluetooth™ antenna, at least one microphone, a digital signal processor,at least one speaker, a speech synthesizer, a voice recognition circuitincluding any voice recognition software, an electrochromic mirror, anelectronic compass, map lamps, a moisture sensor, a headlamp sensor, aback-up power supply, a display, a vehicle bus interface, and an audioprocessing circuit. The present invention broadly pertains not only tovarious combinations of the above features, but also to the variousdisclosed, inherent, and implicit benefits and functions that flow fromsuch features.

According to one embodiment of the present invention, a rearviewassembly is provided for a vehicle. The rearview mirror assemblycomprises a mirror mounting structure including a mirror housing andadapted to be mounted to the vehicle, and an antenna for a wirelesstelephone mounted to the mirror mounting structure.

According to another embodiment of the present invention, a rearviewmirror assembly comprises a mirror mounting structure including a mirrorhousing and adapted to be mounted to the vehicle, and a speechsynthesizer circuit carried by the mirror mounting structure forgenerating synthesized voice audio signals.

According to another embodiment of the present invention, a rearviewmirror assembly comprises a mirror mounting structure including a mirrorhousing and adapted to be mounted to the vehicle, and a voicerecognition circuit carried by the mirror mounting structure and coupledto a microphone for receiving voice signals from a vehicle occupantperforms voice recognition on the received voice signals and generatesdata representing the recognized voice signals.

According to another embodiment of the present invention, a rearviewmirror assembly is provided for a vehicle having an audio system. Themirror assembly comprises a mirror mounting structure including a mirrorhousing and adapted to be mounted to the vehicle, an audio source ofaudio signals carried by the mirror mounting structure, and a wirelessaudio/data RF transmitter carried by the mirror mounting structure andcoupled to the audio source for transmitting audio signals received fromthe audio source via a wireless link to a receiver coupled to the audiosystem for playback on the vehicle's audio system.

According to another embodiment of the present invention, an electricalcircuit is provided for a vehicle that comprises at least one microphonetransducer for generating an electrical signal representing a receivedaudio signal, a processing circuit coupled to the microphone transducerfor processing the electrical signal, a voice recognition circuitcoupled to the processing circuit for performing voice recognition onthe processed electrical signals generated by the processing circuit,and a wireless telephone transceiver coupled to the processing circuitfor transmitting the processed electrical signal through a wirelesstelephone link, wherein the processing circuit processes the electricalsignal received from the microphone transducer differently for output tothe voice recognition circuit than for output to the wireless telephonetransceiver.

According to another embodiment of the present invention, a telephonesystem is provided for a vehicle that comprises a microphone, atelephone transceiver coupled to the microphone, the telephonetransceiver transmits and receives voice signals via a wirelesscommunication link, and a voice recognition circuit coupled to themicrophone and the telephone transceiver, the voice recognition circuitrecognizes spoken words received through the microphone and transmits asignal to the telephone transceiver pertaining to the recognized spokenwords, and wherein the telephone transceiver transmits information overthe wireless communication link in response to the signal received fromthe voice recognition circuit during a telephone call.

According to another embodiment of the present invention, a rearviewmirror assembly for a vehicle comprises a mirror mounting structureadapted to be attached to the vehicle, an electronic circuit mounted tothe mirror mounting structure, and a battery mounted within the mirrormounting structure for supplying power to the electronic circuit.

According to another embodiment of the present invention, an electronicvehicle accessory comprises an electronic circuit configured to receivepower from a vehicle battery or ignition, a back-up battery forproviding power to the electronic circuit when power from the vehiclebattery or ignition is disrupted, and a heater circuit for heating theback-up battery.

According to another embodiment of the present invention, a rearviewmirror assembly for a vehicle comprises a mirror mounting structureadapted to be attached to the vehicle, a telephone transceiver mountedwithin the mirror mounting structure, and an energy storage devicemounted within the mirror mounting structure for supplying power to thetelephone transceiver.

According to another embodiment of the present invention, a vehicleaccessory telephone system comprises an accessory housing, a telephonetransceiver mounted in the accessory housing and configured to receivepower from a vehicle battery or ignition, and a back-up energy sourcemounted in the accessory housing for providing power to the telephonetransceiver to enable the telephone transceiver to transmit a distresscall when power from the vehicle battery or ignition is disrupted.

According to another embodiment of the present invention, a telematicssystem is provided for installation in a vehicle having an electronicmodule configured to control a feature of the vehicle that affects theability of the vehicle to be driven. The telematics system comprises aglobal position identification component for identifying the location ofthe vehicle, a telephone transceiver component coupled to the globalposition identification component for transmitting the location of thevehicle to a remote system, and a controller component coupled to theglobal position identification component and the telephone transceivercomponent, wherein at least one of the components is configured toperiodically communicate with the electronic module and to therebyacknowledge that each of the components is present and functional suchthat if the electronic module does not receive periodic acknowledgementof the presence and/or functionality of the components, the electronicmodule affects the ability of the vehicle to be driven.

According to another embodiment of the present invention, a telematicssystem is provided for installation in a vehicle having an electronicmodule configured to control the ignition of the vehicle. The telematicssystem comprises a global position identification component foridentifying the location of the vehicle, a telephone transceivercomponent coupled to the global position identification component fortransmitting the location of the vehicle to a remote system, and acontroller component coupled to the global position identificationcomponent and the telephone transceiver component, wherein at least oneof the components is configured to communicate with the electronicmodule and to thereby acknowledge that each of the components is presentand functional such that if the electronic module does not receiveacknowledgement of the presence and/or functionality of the components,the electronic module disables the vehicle ignition.

According to another embodiment of the present invention, a telephonesystem for installation in a vehicle having an electronic module fordetermining whether an ignition key has been inserted into the vehicleignition and for communicating the presence of the key in the ignition,the telephone system comprises a telephone transceiver for transmittingcalls over a wireless communication link, and a control circuit coupledto the telephone transceiver and in communication with the electronicmodule, the control circuit disables at least some functions of thetelephone transceiver when an ignition key is not detected in thevehicle ignition.

According to another embodiment of the present invention, a telephonesystem for a vehicle comprises a telephone transceiver mounted to thevehicle, an audio and data transceiver for receiving audio and datasignals from a portable telephone associated with the vehicle, amicrowave receiver for receiving satellite signals from which thelocation of the vehicle may be identified, and a control circuit coupledto the microwave receiver, the audio and data transceiver, and thetelephone transceiver, the control circuit controls operation of thetelephone transceiver and selectively enables and disables certainfunctions of the telephone system in response to information obtainedfrom the microwave receiver.

According to another embodiment of the present invention, a telephonesystem for a vehicle comprises a telephone transceiver mounted to thevehicle, a hands-free microphone coupled to the telephone transceiver,at least one hands-free speaker coupled to the telephone transceiver, anaudio and data transceiver for receiving audio and data signals from aportable telephone associated with the vehicle, and a control circuitcoupled to the audio and data transceiver and the telephone transceiver,the control circuit determines whether a portable telephone having apredetermined identification number is within the range of the audio anddata transceiver and exchanges data with the portable telephone throughthe audio and data transceiver, the control circuit selectively performsfunctions in response to the data exchanged with the portable telephone.

According to another embodiment of the present invention, a vehiclerearview assembly provides an image of a scene to the rear of the driverof the vehicle. The rearview assembly comprises a mounting structure formounting to the vehicle, an audio and data transceiver supported by themounting structure, capable of receiving both audio and data signalsfrom at least one remote device associated with the vehicle, a controlcircuit coupled to the audio and data transceiver, the control circuitprocesses a data signal received by the audio and data transceiver thatare received from a remote device associated with the vehicle, andgenerates a control signal in response to such a data signal.

According to another embodiment of the present invention, a vehiclerearview assembly provides an image of a scene to the rear of a driver.The rearview assembly comprises a mounting structure for mounting to thevehicle, and a telephone transceiver supported by the mountingstructure, wherein the rearview assembly exhibits an electromagneticinterference level less than about 61 dBμV/m for emissions in thefrequency range from about 0.4 MHz to about 20 MHz.

According to another embodiment of the present invention, a vehiclerearview assembly that provides an image of a scene to the rear of adriver comprises a mounting structure for mounting to the vehicle, themounting structure including a housing having an electrically conductivelayer, and a telephone transceiver mounted within the housing.

According to another embodiment of the present invention, a telephonesystem is provided for use in a vehicle having a stereo audio systemwith at least two speakers disposed on opposite sides of the vehicleinterior, the speakers configured to playback one of two stereo audiosignals output from an audio receiver. The telephone system comprises atelephone transceiver mounted in the vehicle and having an audio outputthrough which an audio signal is transmitted for playback on the stereoaudio system, a microphone coupled to the telephone transceiver andmounted in the interior of the vehicle between the at least twospeakers, and a phase inverter coupled to the audio output of thetelephone transceiver and to the audio receiver such that the audioreceiver provides the speaker disposed on one side of the vehicle withan audio signal whose phase is inverted relative to an audio signalprovided to the speaker disposed on the opposite side of the vehicle.

According to another embodiment of the present invention, a method ofconfiguring a hands-free telephone system in a vehicle comprises:providing first and second speakers for generating audible sounds inresponse to an electrical signal, providing a microphone in between thefirst and second speakers, coupling the microphone and the first andsecond speakers to a telephone transceiver, providing an audio outputsignal originating from the telephone transceiver to the first speaker,and inverting the phase of the audio output signal and providing theinverted signal to the second speaker.

According to another embodiment of the present invention, a telephonesystem for use in a vehicle comprises an audio speaker, a telephonetransceiver mounted in the vehicle and having an audio output coupled tothe audio speaker for delivering an audio output signal for playback onthe speaker, an acoustic port acoustically coupled to the speaker so asto project sounds generated by the audio speaker that are out of phasewith respect to the same sounds generated at the audio speaker, and amicrophone coupled to the telephone transceiver and positioned betweenthe audio speaker and the acoustic port.

According to another embodiment of the present invention, a trafficlight warning system for a vehicle comprises a display device, areceiver for receiving a signal from a traffic light proximate thevehicle, the signal indicating the status of the traffic light, and acontrol circuit coupled to the receiver and to the display device fordisplaying the status of a traffic light on the display device.

According to another embodiment of the present invention, a headingindication system for a vehicle comprises a microwave receiverconfigured to receive signals from a global position satelliteconstellation, a turn sensor for sensing turning of the vehicle, acontrol circuit coupled to the microwave receiver and to the turn sensorfor determining vehicle heading from signals received from the microwavereceiver and for generating a control signal representative of thevehicle heading, wherein, when the control circuit determines that thevehicle heading has changed based upon the signals received from themicrowave receiver and when the turn sensor does not sense that thevehicle has turned, the control circuit does not change the controlsignal thereby indicating that the vehicle heading has not changed, anda heading indictor coupled to the control circuit for providing anindication of the vehicle heading in response to the control signal.

According to another embodiment of the present invention, anetwork-aided navigation system for a vehicle comprises a microwavereceiver configured to receive signals from a global position satelliteconstellation, and a wireless communication transceiver coupled to themicrowave receiver for transmitting signals corresponding to the signalsreceived by the microwave receiver to a network processor, and forreceiving signals from the network processor from which the location ofthe vehicle may be derived.

According to another embodiment of the present invention, a navigationsystem for a vehicle comprises a control circuit for supplying traveldirections, and a speech synthesizer coupled to the control circuit forreceiving the travel directions and for reproducing the traveldirections in an audible speech message.

According to another embodiment of the present invention, a navigationsystem for a vehicle comprises a navigation circuit for providingnavigational information to a driver of the vehicle based in part oninformation stored in a navigation database, and a wirelesscommunication transceiver coupled to the navigation circuit forreceiving navigational data from a remote source and for supplying thereceived navigational data to the navigation circuit for storage in thenavigation database.

According to another embodiment of the present invention, a blackboxrecorder for a vehicle comprises a camera mounted to the vehicle forimaging a scene proximate or within the vehicle, and a non-volatilememory device for storing information pertaining to the vehicleincluding at least one image obtained from the camera.

According to another embodiment of the present invention, a blackboxrecorder for a vehicle comprises a camera mounted to the vehicle forimaging a scene proximate or within the vehicle, a memory device forstoring information pertaining to the vehicle including at least oneimage obtained from the camera, and a back-up battery for providingpower to the blackbox recorder in the event of a disruption of powersupplied from a primary power source in the vehicle.

According to another embodiment of the present invention, a blackboxrecorder for a vehicle comprises a memory device for storing informationpertaining to the vehicle including at least one of vehicle speedhistory, vehicle rollover indication, air bag deployment indication, anddeceleration data.

According to another embodiment of the present invention, a vehiclerearview assembly that provides an image of a scene to the rear of thedriver of the vehicle, comprises a first switched power supply operatingat a first frequency, and a second switched power supply operating at asecond frequency, wherein the first frequency is a multiple of thesecond frequency and the first and second switched power supplies aresynchronized.

According to another embodiment of the present invention, a rearviewassembly that provides an image of a scene to the rear of the driver ofa vehicle, comprises a housing for housing an imaging component thatprovides the image of a scene to the rear of the driver of the vehicle,and a mounting bracket for mounting the housing to the vehicle, themounting bracket having two rotary joints, wherein the housing has amass in excess of 580 grams.

According to another embodiment of the present invention, a rearviewassembly that provides an image of a scene to the rear of the driver ofa vehicle, comprises a mounting structure adapted for mounting to thevehicle, a pushbutton mounted on the mounting structure, and a controlcircuit coupled to the pushbutton for performing a selected function inresponse to actuation of the pushbutton, wherein the control circuit isprogrammable to allow personalization of the selected function that isperformed in response to actuation of the pushbutton.

According to another embodiment of the present invention, a rearviewassembly that provides an image of a scene to the rear of the driver ofa vehicle, comprises a mounting structure adapted for mounting to thevehicle, a pushbutton mounted on the mounting structure, a controlcircuit coupled to the pushbutton for performing a selected function andgenerating a display signal representing the function to be performed inresponse to actuation of the pushbutton, and a display supported by themounting structure and coupled to the control circuit for displaying thefunction to be performed by the control circuit a mounting structureadapted for mounting to the vehicle, a pushbutton mounted on themounting structure, and a control circuit coupled to the pushbutton forperforming a selected function in response to actuation of thepushbutton, wherein the control circuit is programmable to allowpersonalization of the selected function that is performed in responseto actuation of the pushbutton.

According to another embodiment of the present invention, a rearviewassembly that provides an image of a scene to the rear of the driver ofa vehicle, comprises a housing for housing an imaging component thatprovides the image of a scene to the rear of the driver of the vehicle,and a mounting bracket for mounting the housing to the vehicle, whereinthe housing includes a contoured wall defining an interior cavity, thewall having a thickness that is non-uniform and that is greater at acentral region to which the mounting bracket attaches to the housingthan at other regions of the housing.

According to another embodiment of the present invention, a rearviewassembly that provides an image of a scene to the rear of the driver ofa vehicle, comprises a mounting structure for mounting to the vehicle,and a display circuit supported by the mounting structure for displayinginformation to occupants of the vehicle, the display circuit configuredto display at least ten characters simultaneously and to operate at avoltage of less than 42 volts.

According to another embodiment of the present invention, a telephonesystem for a vehicle comprises a transparent antenna including atransparent substrate having at least one electrically conductive regionconfigured to receive RF signals from a wireless telephone network andto transmit RF signals to the wireless telephone network, and atelephone transceiver coupled to the transparent antenna and mounted inthe vehicle.

According to another embodiment of the present invention, a globalposition system for a vehicle comprises a transparent antenna includinga transparent substrate having at least one electrically conductiveregion configured to receive microwave signals from satellites of aglobal position system constellation, and a microwave receiver coupledto the transparent antenna and mounted in the vehicle.

These and other features, advantages, and objects of the presentinvention will be further understood and appreciated by those skilled inthe art by reference to the following specification, claims, andappended drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings:

FIG. 1 is a cut-away perspective view of a vehicle in which a rearviewmirror assembly is mounted;

FIG. 2A is a perspective side view of a rearview mirror assembly;

FIG. 2B is a perspective side view of another rearview mirror assembly;

FIG. 3 is a cross-sectional view of the mounting foot of a rearviewmirror assembly;

FIG. 4 is a perspective view of the forward-facing portion of themounting foot of the rearview mirror assembly shown in FIG. 3;

FIG. 5 is a rearward perspective view of the rearview mirror assemblyshown in FIG. 2A;

FIG. 6 is a partially exploded perspective view of the rearview mirrorassembly of the present invention;

FIG. 7A is an elevational view of the front of a rearview mirrorassembly constructed in accordance with a preferred embodiment of thepresent invention;

FIG. 7B is a side elevational view of the side of the rearview mirrorshown in FIG. 7A;

FIG. 7C is a top plan view showing the top of the rearview mirrorassembly of FIGS. 7A and 7B;

FIG. 7D is an elevational view showing the rear of the rearview mirrorassembly shown in FIGS. 7A-7C;

FIG. 8A is an elevational view showing the front of a rearview mirrorhousing shell that may be used in the rearview mirror assembly of thepresent invention;

FIG. 8B is a top plan view showing the top of the rearview mirrorhousing shell of FIG. 8A;

FIG. 8C is a plan view showing the bottom of the rearview mirror housingshell shown in FIGS. 8A and 8B;

FIG. 8D is an elevational view showing the rear of the rearview mirrorhousing shell shown in FIGS. 8A-8C;

FIG. 8E is a cross-sectional view of the rearview mirror housing shellshown in FIG. 8D taken along line E-E′;

FIG. 9A is an elevational view showing the front of the internalcomponents contained within the rearview mirror assembly of the presentinvention;

FIG. 9B is a cross-sectional view of the internal component and aportion of the housing of the components shown in FIG. 9A taken alongline B-B′;

FIG. 9C is a cross-sectional view of the internal component and aportion of the housing of the components shown in FIG. 9A taken alongline C-C′;

FIG. 9D is a side elevational view showing the components of theinventive rearview mirror assembly;

FIG. 9E is a rear elevational view showing the interior components ofthe rearview mirror assembly;

FIG. 9F is a bottom plan view showing the bottom of the components ofthe inventive rearview mirror assembly;

FIG. 10A is an elevational view showing the front of an antennastructure 114 a that may be used in the inventive rearview mirrorassembly;

FIG. 10B is a side elevational view of the antenna structure shown inFIG. 10A;

FIG. 10C is a front elevational view showing the internal antennastructures contained within the internal antennas shown in the antennastructure of FIGS. 10A and 10B;

FIG. 10D is a front perspective view of an antenna structure 114 bconstructed in accordance with another embodiment of the presentinvention;

FIG. 10E is a side perspective view of the antenna structure 114 b shownin FIG. 10D;

FIG. 10F is a perspective view showing the rear surface of the antennastructure 114 b shown in FIGS. 10D and 10E;

FIG. 10G is a perspective view showing the front of an antenna structure114 c constructed in accordance with another embodiment of the presentinvention;

FIG. 10H is a perspective view showing the rear of the antenna structureshown in FIG. 10G;

FIG. 11 is an electrical circuit diagram in block form showing anembodiment of the vehicle communication and control system of thepresent invention;

FIG. 12 is an electrical circuit diagram in block form showing anexemplary electrochromic mirror/compass system for use with the presentinvention;

FIG. 13 is an electrical circuit diagram in block form showing variouselectrical systems that may be coupled to the inventive vehiclecommunication and control system shown in FIG. 11;

FIG. 14 is a graphical illustration of currently acceptable EMI levelsfor both narrowband and broadband emissions in a rearview mirrorassembly;

FIG. 15 is a graphical illustration of a typical narrowband EMI emissionspectrum;

FIG. 16 is a graphical illustration of a typical broadband EMI emissionspectrum;

FIG. 17 is a perspective view of a rearview mirror constructed inaccordance with another embodiment of the present invention; and

FIG. 18 is a perspective view of a rearview mirror constructed inaccordance with another embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Reference will now be made in detail to the present preferredembodiments of the invention, examples of which are illustrated in theaccompanying drawings. Wherever possible, the same reference numeralswill be used throughout the drawings to refer to the same or like parts.

As noted above, the present invention pertains to a vehicle rearviewassembly that incorporates some or all of the components of a vehiclecommunication and control system. As used herein, a “rearview assembly”is a structure that provides an image of a scene to the rear of driver.As commonly implemented, such rearview assemblies include anappropriately positioned mirror. A rearview assembly may additionally oralternatively include an electronic display that displays an image assensed by a camera or other image sensor (see, for example, U.S. patentapplication Ser. No. 09/153,654 entitled SYSTEMS AND COMPONENTS FORENHANCING REAR VISION FROM A VEHICLE, filed on Sep. 15, 1998, byFrederick T. Bauer et al., the entire disclosure of which isincorporated herein by reference). As will be apparent to those skilledin the art, certain aspects of the present invention may be implementedin vehicle accessories other than a rearview assembly, such as anoverhead console, a visor, an A-pillar trim panel, an instrument panel,etc. With respect to those implementations, the discussion belowrelating to rearview mirror assemblies is provided for purposes ofexample without otherwise limiting the scope of the invention to suchrearview assemblies.

In some of the embodiments described below, the “brick” of suchcommunication and control systems is integrated into a rearviewassembly. Preferably, the GPS receiver and microwave antenna, as well asthe cellular telephone antenna, are mounted to the rearview assembly. Byintegrating all of these components into the rearview assembly, the needfor running extensive wiring through the vehicle is essentiallyeliminated. Furthermore, the whole system may be readily installed as avehicle option by the vehicle manufacturer, the dealer, or anyonebuying/selling the product as an after-market product. Other advantagesof the invention are described further below.

Rearview Assembly Construction

An example of an inside rearview mirror assembly constructed inaccordance with one embodiment of the present invention is shown inFIGS. 1-6. FIG. 1 shows the general mounting of rearview mirror assembly10 to the inside surface of a front windshield 20 of a vehicle 25. FIGS.2A and 2B show two different exemplary rearview mirror assemblyconstructions in which the microwave antenna may be mounted. Morespecifically, rearview mirror assembly 10 a shown in FIG. 2A is designedto be mounted directly to windshield 20, whereas rearview mirrorassembly 10 b shown in FIG. 2B is mounted to the roof of the vehicle.

In general, rearview mirror assemblies include a mirror housing 30 thatmay have a wide variety of the possible designs, such as, for example,the mirror housing taught and claimed in U.S. Pat. No. 5,448,397.Rearview mirror assemblies also include a mirror 40 (FIG. 5) mounted inmirror housing 30, and a mounting bracket 35 that attaches mirrorhousing 30 to the vehicle. Such mounting brackets typically include amounting foot 36 that is directly mounted to the vehicle and to a mirrorstem 38 that extends between mounting foot 36 and mirror housing 30. Asapparent from a comparison of FIGS. 2A and 2B, the structure of mountingfoot 36 and mirror stem 38 may vary considerably from one rearviewmirror assembly to the next. For example, mirror stem 38 may bepivotally mounted to mounting foot 36 as shown in FIG. 2A or fixedlyattached to mounting foot 36 as shown in FIG. 2B. Additionally, mirrorhousing 30 is typically pivotally attached to mirror stem 38. Suchpivotal attachments allow the driver to move and position the mirror soas to allow the driver to a have a clear field of view towards the rearof the vehicle. The disclosed rearview mirror assembly also preferablyincludes a display 45 (FIG. 5) housed within mirror housing 30 or housedwithin mounting foot 36. As shown in FIGS. 2A, 2B, and 6, mirror housing30 may include a mirror housing body 31 and a bezel 32 that is mountedto mirror housing body 31 so as to secure mirror 40 and all thecomponents in mirror housing 30.

FIG. 6 shows an exemplary mechanical construction of mirror housing 30of rearview mirror assembly 10. As illustrated, the following componentsare mounted in or on mirror housing 30: a mirror element 40; a firstprinted circuit board 110; a second printed circuit board 112; a firstRF antenna 114; a second RF antenna 116; and first and second map lamps118 a and 118 b. A microphone assembly 140 may be mounted to the bottomor top of mirror housing 30. Microphone assembly 140 is described inmore detail below under the heading “Microphone Subassembly.” As shown,mirror housing 30 is secured to mirror stem 38 by means of a bolt 37 anda washer 39. It will be appreciated, however, that any suitable meansmay be utilized to mount mirror housing 30 to mirror stem 38.

Although antennas 114 and 116 are shown as being oriented horizontallyand having a generally linear shape (as would be true if the antennaswere strip antennas), those skilled in the art will appreciate thatthese RF antennas may be helical or take any suitable form forperforming the functions that are described further below. Also, eitherone or both of antennas 114 and 116 may be mounted to the exterior ofthe rearview mirror assembly.

A rearview mirror assembly 10 c constructed in accordance with apreferred embodiment is shown in FIGS. 7-9. Like the mirror assemblyshown in the previous embodiment, rearview mirror assembly 10 c includesa mirror housing 30 a and a mirror 40, which is preferably anelectrochromic mirror. Assembly 10 c further includes a display 45, aforward bezel portion 32 of housing 30 a, a plurality of userpushbuttons 130, and a glare sensor 124. Rearview mirror assembly 10 cfurther includes a microphone assembly 140 a, which is described furtherbelow, an antenna structure 114 a, an LED indicator 152, and an optionalcamera housing 154. Camera housing 154 is provided for housing an imagesensor array for automatically controlling the beam pattern of thevehicle's exterior lights (i.e., low beam headlamps, high beamheadlamps, daytime running lights, fog lights, etc.). A more detaileddescription of such a subassembly and the manner in which it ismechanically attached to a rearview mirror assembly is provided incommonly assigned U.S. patent application Ser. No. 09/800,460(unofficial) filed on Mar. 5, 2001, by Joseph S. Stam et al. entitledSYSTEM FOR CONTROLLING EXTERIOR VEHICLE LIGHTS, the entire disclosure ofwhich is incorporated herein by reference.

As best shown in FIGS. 7B and 7D, camera housing 154 includes an openingfor a sky sensor 129, which senses the ambient light level of the skyabove and slightly forward of the vehicle. Additionally, a window 155 isprovided through which the camera receives the light from the forwardscene to be imaged. As described in more detail in the above-referencedpatent application, camera housing 154 is secured to a mounting foot 52of a mounting bracket 35. Mounting foot 52 includes a first rotary balljoint 158 that extends rearward from a surface of foot 152 opposite fromthe vehicle windshield. Ball 158 is received in a corresponding socketof a stem 38, which in turn includes a second rotary ball joint 156,which is received by a hub 162 (FIG. 9F) provided within mirror housing30 a.

As described in further detail below, a top middle portion of mirrorhousing 30 a is substantially flat to provide a flat surface 301 uponwhich microphone subassembly 140 a may be mounted. A rearward rim ofsurface 301 includes an air deflector 300 as also described furtherbelow. As best shown in FIGS. 8A-8D, an aperture 302 is provided in flatsurface 301 for receiving microphone subassembly 140 a. Surrounding theaperture 302 is a strengthening rim 303 that adds to the structuralintegrity of mirror housing 30 a to provide sufficient support formicrophone subassembly 140 a and to receive tabs extending from thebottom of microphone subassembly 140 a such that the microphonesubassembly 140 a may be snapped into place within aperture 302. As bestshown in FIGS. 9B and 9C, microphone subassembly 140 a further includesa circuit board 304 on which the transducers and associated microphonecircuit components are mounted.

Referring back to FIGS. 7A, 7C, and 7D, an antenna structure 114 a maybe mounted so as to extend upward from a rear portion of mirror housing30 a. A relatively flat surface 150 a may be formed in a portion of therear of housing 30 a for receiving antenna structure 114 a. A preferredconstruction for antenna structure 114 a is described below withreference to FIGS. 10A-10C.

As best shown in FIGS. 7C and 7D, housing 30 a includes an aperture 160a through which a connector receptacle 160 is accessible. An additionalaperture 126 a is formed in housing 30 a to allow light to strike anambient light sensor 126, which is discussed further below.

FIGS. 8A-8D show the detailed interior and exterior shell of mirrorhousing 30 a. FIG. 8A represents the view of the housing shell whenviewing it from the direction in which the mirror would normally belocated so as to see the interior view of the sides and back portion ofhousing 30 a. FIG. 8B illustrates a top view of housing 30 a, while FIG.8C shows the bottom of housing 30 a. FIG. 8D shows housing 30 a from therear of the housing that faces the vehicle windshield. FIG. 8E is across-sectional view taken along line E-E′ of FIG. 8D.

As discussed further below with reference to FIGS. 9A-9F, the amount ofcircuitry contained within mirror housing 30 a is significantlyincreased over that previously provided in a rearview mirror assembly.Consequently, the total mass of mirror housing 30 a is significantlyhigher than the mass of prior art rearview mirror housings. The heaviestrearview mirror housing assembly of which the inventors are awareincluded various electrical components as well as an electrochromicmirror. This housing had a mass of approximately 565 grams. A prototypeof the present invention was weighed, which did not include the antennastructure shown in the drawing figures. The mass of this prototype wasapproximately 630 grams. Thus, the mirror housing of the presentinvention may have a mass of at least about 580 grams.

This increase in mass creates several mechanical difficulties. First,housing 30 a must be made larger and deeper than previous rearviewmirror assemblies in order to accommodate the additional circuitrycontained within the mirror housing. This increase in size of housing 30a requires additional strengthening components to minimize addedtorsional stresses that may be applied to the mirror, for example, aswould occur when one were to grab opposite ends of the mirror and twistthe sides in opposite directions. One manner to increase the strength ofhousing 30 a would be to simply increase the thickness of the walls 30 bof housing 30 a. However, merely increasing the thickness of walls 30 dwould unduly add to the weight of the whole housing assembly.

Another problem associated with added mass of the mirror housing 30 a isthat the mirror housing is more likely to vibrate. Such vibration tendsto blur the image viewed by the driver through the mirror 40. Further,the rotational joints that allow mirror housing 30 a to pivot relativeto the mounting bracket and to the vehicle at one or more positions mustbe all the more snug to maintain the position of the mirror housing 30 ain the position set by the driver.

The housing should additionally be configured to allow for easy assemblyof the various components to mirror housing 30 a.

The mirror housing 30 a depicted in FIGS. 8A-8E overcomes these problemsby employing various measures. Specifically, with reference to FIG. 8A,housing 30 a includes several strengthening ribs 164 that extendradially outward from the center of an aperture 162 a where ball 156 ofstem 38 is received by hub 162. While prior art mirrors previouslyutilized similar ribs, ribs 164 of the present invention are much deeperto improve the structural rigidity of the housing shell. Additionally,the housing shell includes walls 30 b that are thicker in the areasurrounding aperture 160 a and that become thinner near the peripheralforward opening to which bezel portion 32 is attached along with mirror40. Such a variation in thickness is illustrated in FIG. 8E.Additionally, various strengthening rims are provided around the variousapertures formed in housing 30 a to provide additional mechanicalstability. As shown in FIGS. 9B-9F, at least two circuit boards 110 and112 are provided within mirror housing 30 a. Second circuit board 112may include a plurality of pins, screws, or holes 148 (FIG. 9E) throughwhich pins or screws may be inserted that correspond in position tothreaded apertures 149 (FIG. 8A) extending from the inside rear wall ofhousing 30 a. This allows circuit board 112 to be secured in place inmirror housing 30 a following installation of hub 162. Hub 162 maysimilarly be screwed in place using threaded apertures provided inhousing 30 a. The first circuit board 110 may then be held in place byconnector pins and receptacles 166 provided on each of first and secondcircuit boards 110 and 112. Alternatively, first circuit board 110 couldbe separately attached to housing 30 a or otherwise attached to the rearsurface of electrochromic mirror 40. As shown in FIGS. 9A-9F, connectorreceptacle 160 and ambient light sensor 126 may be mounted to a rearsurface of first circuit board 110 so as to be aligned with and extendto the corresponding apertures 160 a and 126 a in housing 30 a. To allowfor the components to be as compact as possible within housing 30 a, anyof the larger circuit components on circuit board 110 are preferablymounted in the peripheral regions of the rear surface of circuit board110 in areas not covered by second circuit board 112.

By mounting second circuit board 112 directly to the inside rear surfaceof housing 30 a across a substantial portion thereof, particularlyacross the central rear region where hub 162 receives ball 156, circuitboard 112 can add to the structural rigidity of the housing assembly. Asshown in FIGS. 9B-9F, second circuit board 112 may be encased within anelectrically conductive casing 112 a that is secured on both sides ofcircuit board 112 so as to provide shielding from electromagneticinterference (EMI). Casing 112 a may be made of metal or a metal-coatedplastic. As discussed further below, the inside surface of mirrorhousing 30 a may be coated with an electrically conductive coating orpaint to provide additional EMI shielding. The electrically conductivecoating on the inside of mirror housing 30 a may also provide theadditional function of serving as the ground plane for the antennascontained within antenna structure 114 a. Such an electrical coating ofthe inside of housing 30 a may be provided as an alternate measure ofproviding EMI shielding or as an additional measure to providing casing112 a.

In the exemplary structure shown in FIGS. 9A-9F, second circuit board112 preferably includes all the electronic components for the cellulartelephone. Other components of the circuit described in more detail inFIG. 11 may be provided on either of circuit boards 110 or 112. Toenable more components to be mounted to the two circuit boards, eitherone or both of circuit boards 110 and 112 may be double-sided circuitboards that allow components to be mounted on either side of the board.Additionally, the present invention is not limited to utilizing only twocircuit boards, and additional circuit boards may be included.

As shown in FIGS. 9A, 9C, 9D, and 9F, a plurality of switches 130 b ismounted to the forward facing surface of first circuit board 110 inpositions that correspond to pushbuttons 130. Pushbuttons 130 include aninward extending plunger 130 a (see FIG. 9C) that pushes against anactuator in switch 130 b when a user presses pushbutton 130. Display 45is mounted on circuit board 110 so as to be viewable either from behindmirror 40 or from a position adjacent mirror 40 in bezel portion 32. Aswill be apparent to those skilled in the art, once all the electroniccircuitry and microphone subassembly 140 a have been appropriatelyattached to housing shell 30 a, and the appropriate electricalconnections are made, mirror 40 may be placed over the opening inhousing 30 a, and bezel portion 32 may be snapped into position acrossthe opening of housing shell 30 a. Alternatively, mirror 40 and bezelportion 32 may be preassembled and then subsequently snapped into placetogether as a unit.

FIGS. 10A-10C illustrate a preferred antenna structure 114 a that may beused as the antenna for the cellular telephone contained within themirror housing. As illustrated, antenna structure 114 a preferablyincludes two antenna portions 161 a and 161 b that are shaped as quarterwave strips resembling inverted triangles or wedges so as to function asa broadband antenna. Antenna portions 161 a and 161 b may also befractal. Specifically, first antenna portion 116 a is configured to betuned to frequencies of approximately 800 MHz while antenna portion 161b is configured to be tuned to frequencies of approximately 1.9 GHz,which correspond to signals from PCS devices. Antenna portions 161 a and161 b are preferably encapsulated in a plastic antenna housing 150,which is preferably made of the same or like materials as housing shell30 a so as to provide a similar and aesthetically pleasing appearance.Antenna housing 150 is preferably molded to include at least tworesilient tabs 169 that allow the antenna structure 114 a to be snappedin place in a corresponding aperture formed in mirror housing 30 a. Oneor more leads 168 extends downward from antenna housing 150 from antennaportions 161 a and 161 b for engagement with a contact in a receptacleplug provided on one of the first or second circuit boards 110 and 112provided in housing 30 a. Such a construction may eliminate the need fora coaxial cable connection. With the antenna construction shown in FIGS.10A-10C, the mirror housing is coated with a metallic coating so as toserve as the ground plane for the antenna. In addition to providing anantenna for the internal telephone provided within housing 30 a, anadditional antenna may be provided in housing 150 to allow reception ofBluetooth™ signals.

Antenna structure 114 a may be mounted in other locations of therearview mirror assembly or may be mounted elsewhere in the vehicle. Forexample, the antenna may be configured as a transparent antenna andintegrated in a structure with the GPS antenna in a manner similar tothat illustrated in FIGS. 10D, 10E, and 10F. Specifically, thetransparent structure includes a transparent substrate 400 preferablymade of a transparent polymer, a dual band antenna structure 402 havingdimensions and structure similar to that shown in FIG. 10C, a GPS patchantenna 404, lead lines 406 and 408, and contact terminals 410 and 412.Dual band cellular antenna 402, GPS antenna 404, lead lines 406 and 408,and contact terminals 412 and 410 are preferably formed on a firstsurface of substrate 400 and are formed of an electrically conductivematerial. The electrically conductive material may be provided onsubstrate 400 by selectively metallizing the regions of the firstsurface of substrate 400 in those regions defining the antennas, leads,and contact terminals. “Metallizing” should be understood to includeapplication of transparent conductive coatings such as Indium Tin Oxide(ITO). Very thin, nearly transparent layers of metal such as gold mayalso be used. One suitable substrate material is polymethylpentene, alsoknown as TPX. A low loss material, such as TPX, is desirable toconstruct an efficient GPS patch antenna. Other antenna structures, suchas monopoles, which do not form high Q resonant cavities (as is the casefor a patch antenna), may be constructed using higher loss materialssuch as polyester (Mylar). The antenna system may also be a hybridsystem where part of the antenna or ground plane is opaque. As shown inFIGS. 10E and 10F, the opposite surface of substrate 400 may also becoated with an electrically conductive material to provide a groundplane 415. The transparent substrate 400 may serve as a dielectric layerbetween patch antenna 404 and ground plane 415 or an optional dielectriclayer may be formed between patch antenna 404 and substrate 400. A smallregion 416 underlying contact terminal pads 410 and 412 may be leftdevoid of the ground plane conductive material 415 so as to provide forease of connection of respective coaxial cables or other connectionmeans.

Dual band cellular antenna 402 may be configured in any shape or fashionand is generally shown as having a similar broadband structure includingtwo wedge-shaped micro strips 418 a and 418 b. As noted above, any oneor all of the conductive components may be transparent or opaque andused in combination on a common substrate. The construction shown inFIGS. 10D-10F is preferred in that it allows dual band cellular antenna402 and GPS patch antenna 404 to share a common ground plane 415. Itwill be appreciated, however, that the two antennas may be provided onseparate substrates or otherwise totally separated from one another withone being an opaque and different structure similar to those disclosedabove while the other may be transparent. Any of the above antennas mayincorporate a transparent micro strip transmission line for connectionto the receiver. The micro strip transmission line may be terminated todouble-sided, low or zero insertion force connectors such as an AVXSeries 8370 connector.

By utilizing the transparent antenna system disclosed in FIGS. 10D-10F,the antenna system can cover a larger area of the windshield than anopaque antenna system without becoming objectionable. A largertransparent antenna may have better performance than an opaque systemwhose size is constrained by aesthetic rather than engineeringconsiderations. The transparent antenna system can be easily installedin an after-market application and may offer cost advantages over asystem integrated in the windshield.

An alternative antenna construction 114 c is illustrated in FIGS. 10Gand 10H. This construction is similar to that shown in FIGS. 10D-10F,however, the structure is not formed on a transparent substrate. Morespecifically, the structure is formed on a dielectric substrate 450. Theantenna structure includes a dual band cellular antenna 452 includingtwo straight micro strips 454 a and 454 b provided on a first side ofsubstrate 450. The ground plane 456 is provided on either side of aportion of substrate 450. A GPS patch antenna 460 is provided on anopposite surface of substrate 450 than ground plane 456. A pair of coaxconnectors 462 and 464 is connected to the respective antennas.Resistors and other circuit components may be formed on this structureas may be desired. The telephone antenna may have any shape orconfiguration including a planar, inverted “F” antenna (PIFA).

Microwave Antenna

As shown in FIGS. 3 and 4, a microwave antenna 50 is preferably mountedwithin mounting foot 36 of mounting bracket 35 of rearview mirrorassembly 10 a, 10 b, 10 c. As shown in FIG. 3, mounting foot 36 includesa mounting portion 52 and an antenna housing portion 54. The structureof mounting portion 52 is shown as being configured to attach to amounting puck or button 56 that is attached to the inside surface ofwindshield 20 using an adhesive. Puck 56 includes an inclined edgesurface 57 and a threaded aperture 58 formed in the surface of puck 56opposite that which is adhered to windshield 20. Mounting portion 52thus has an aperture 60 for engaging puck 56. One edge 62 of aperture 60has a sloped profile so as to engage inclined edge surface 57 of puck56. In this manner, the size of aperture 60 is slightly smaller than thearea of the surface of puck 56 that is opposite that which is secured towindshield 20. To then secure mounting portion 52 to puck 56, a setscrew 66 is slid into an aperture 64 formed in mounting portion 52 andturned so as to thread into threaded aperture 58 on puck 56.

Antenna housing portion 54 of mounting foot 36 may be integrally formedwith mounting portion 52 or formed as a separate component that may beattached to mounting portion 52. Antenna housing portion 54 includes anaperture 70 having a generally square, rectangular, or round shape orany other shape for accommodating the particular shape of antenna 50.Aperture 70 is provided so as to open towards windshield 20 throughwhich microwave signals from satellites may pass to reach microwaveantenna 50. Antenna 50 may be mounted in aperture 70 so as to besubstantially parallel to, and slightly spaced apart from, the innersurface of windshield 20. Preferably, antenna 50 is mounted horizontallyin housing portion 54 and has a ground plane configured as disclosed incommonly assigned U.S. patent application Ser. No. 09/535,999, entitledMICROWAVE ANTENNA FOR USE IN A VEHICLE, filed on Mar. 28, 1999, theentire disclosure of which is incorporated herein by reference. Thestructure of antenna 50 is discussed further below.

As shown in FIG. 3, a foam pad 72 or other non-conductive substrate isplaced within antenna housing portion 54 between antenna 50 and theinside surface of windshield 20. As shown in FIG. 4, antenna mountingportion 54 also includes a gasket 74 provided about the periphery ofaperture 70, so as to provide for additional protection against moistureor debris coming between windshield 20 and antenna 50.

In addition to providing space for accommodating antenna 50, mountingfoot 36 is configured to provide sufficient space for a receiver circuit80 printed on a circuit board 82. Circuit board 82 is thus mounteddirectly behind antenna 50 in antenna mounting portion 54, so as tominimize the length of antenna connector 84 that extends between antenna50 and printed circuit board 82.

Because receiver circuit 80 converts the signals received by antenna 50into signals that may be transmitted over conventional wires, theinformation obtained from the satellite signals may be transmitted toother components in the vehicle via the vehicle bus, discreteconnections, an IR transmitter 134 (FIG. 11), or an RF transmitter 185(FIG. 11). More specifically, if a display 45 or additional circuitry,such as a control circuit for an electrochromic mirror or electroniccompass, is mounted in mirror housing 30, receiver circuit 80 may becoupled to such circuitry via a connector line 85 that may be runbetween mounting foot 36 and mirror housing 30 outside of mirror stem 38or internally through mirror stem 38 as disclosed in U.S. Pat. No.5,984,482. Additionally, data processed by receiver circuit 80 may betransmitted via line 86 to other electrical systems within the vehicle.Mirror assembly 10 may include a shroud 88 that extends from mountingfoot 36 to the vehicle headliner, so as to provide a covert channel forrunning cabling 86 between rearview mirror assembly 10 and the remainderof the vehicle.

As shown in FIGS. 3 and 4, microwave antenna 50 is constructed as apatch antenna including a dielectric substrate 90 having a layer of aconductive material provided on one side of dielectric substrate 90 soas to form a resonant patch 92. Antenna 50 further includes a layer ofelectrically conductive material on the opposite side of dielectricsubstrate 90, which forms a conductive ground plane 94 for antenna 50.

By mounting microwave antenna 50 to the mounting bracket of an insiderearview mirror assembly, the antenna has a clear view through thesloped front windshield of much of the sky above and in front of thevehicle. Additionally, the front windshield of the vehicle protects theantenna from dirt, moisture, snow, and humid air that may readily reachthe microwave antenna and adversely affect its performance if it ismounted in a component on the exterior of the vehicle.

In some implementations, it may be preferred to also mount the antennafor the telephone subsystem in antenna housing portion 54. By mountingboth the microwave and telephone antennae in the same housing, any EMIshielding that is provided between microwave antenna 50 and theelectronics in housing 30, may likewise shield the telephone antenna.

Microphone Subassembly

The microphone subassembly used in the present invention may or may notbe mounted in the rearview mirror assembly. For the reasons describedbelow, it is preferable to mount the microphone subassembly on therearview mirror assembly. If the microphone subassembly is not mountedin the rearview mirror assembly, it may be incorporated in or attachedto the headliner, overhead console, visor, or A-pillar of the vehicleand electrically coupled to the components in the rearview mirrorassembly by a wire. When the microphone is installed after vehiclemanufacture and fastened to the headliner or visor, the position of themicrophone may vary depending on where the user installs the microphone.Such potential for variance makes it very difficult to design an optimalsystem. The position of the microphone relative to the person speakingdetermines the level of the speech signal output by the microphone andmay affect the signal-to-noise ratio. Additionally, the position of themicrophone relative to the audio speaker used for the hands-freeoperation will have an impact on feedback between the speaker and themicrophone. Accordingly, the performance of the audio system is subjectto the user's installation of the microphone. Additionally, the wireconnecting the microphone to the rearview mirror will generally not beaesthetically pleasing. Alternatively, if the wire is to be mountedbehind the interior lining, the vehicle interior must be disassembledand then reattached so that the wire can be hidden, which may result inparts that rattle loudly or hang loosely from the vehicle frame.

One potential solution to avoid these difficulties is disclosed in U.S.Pat. No. 4,930,742, which uses a microphone in a mirror mountingsupport. Conceivably, such a structure could be used in combination withcertain aspects of the present invention. Although locating themicrophone in the mirror support provides the system designer with amicrophone location that is known in advance and avoids the problemsassociated with mounting the microphone after the vehicle ismanufactured, there are a number of disadvantages to such anarrangement. Because the mirror is positioned between the microphone andthe person speaking into the microphone, a direct unobstructed path fromthe user to the microphone is precluded. Additionally, the location ofthe microphone on the windshield detrimentally impacts microphone designflexibility and the overall noise performance of the microphone.

As discussed further below, it is desirable to provide a voicerecognition circuit for use with a vehicle communication system, andmost preferably, such a circuit would enable hands-free operation.Hands-free operation of a device used in a voice recognition system is aparticularly challenging application for microphones, as the accuracy ofa voice recognition system is highly dependent upon the quality of theelectrical signal representing the user's speech. Conventionalhands-free microphones are not able to provide the consistency andpredictability of microphone performance needed for such an applicationin a controlled environment such as an office, let alone in uncontrolledenvironments, such as in an automobile.

Commonly assigned U.S. patent application Ser. No. 09/444,176, entitledVEHICLE ACCESSORY MICROPHONE, filed on Nov. 19, 1999, by Robert R.Turnbull et al. (hereinafter “the '176 application”) and commonlyassigned U.S. patent application Ser. No. 09/724,119, entitled VEHICLEACCESSORY MICROPHONE, filed on Nov. 28, 2000, by Robert R. Turnbull etal. (hereinafter “the '119 application”) disclose various microphonesubassembly constructions that are suitable for use in voice recognitionapplications within a vehicle. The entire disclosures of both of theseapplications are incorporated herein by reference. The preferredmounting location for the microphone assemblies disclosed in the '176and '119 applications is on the mirror housing. The mirror housing is adesirable location not only because it allows for a self-containedsystem as described above, but also because a driver will typicallyadjust the position of the mirror housing to reflect images visiblethrough the rear window of the vehicle and thereby will simultaneouslydirect the front of the microphone subassembly toward the driver.

The '176 and '119 applications disclose a number of different microphonesubassembly constructions. A first construction includes two transducersthat are mounted so as to both receive the same in-phase pressure wavesthat correspond to mechanical vibration-induced noise. The electricaloutputs of the two transducers are subtracted from one another such thatthe resultant electrical signal eliminates noise caused by suchvibration. Additionally, the transducers are positioned relative to oneanother such that the transducers receive the driver's speech out ofphase so that the subtraction of the output of one transducer relativeto the other effectively increases the gain of the speech.

A second microphone subassembly construction disclosed in the '176 and'119 applications is a second order directional construction whereby twotransducers are positioned such that the central axes of the transducersare coaxial with one another and are directed towards the mouth of thedriver. The electrical outputs of the two transducers are subtractedfrom one another such that any noise coming in from the sides, which isdetected in phase by the two transducers, is electrically nulled. Thetwo transducers in this construction may be super-cartioid-typetransducers so as to have reduced sensitivity to the rear direction andhave enhanced sensitivity in the forward direction towards the driver.As explained in the '176 and '119 applications, certain frequencieswithin the speech of the driver are detected out of phase with oneanother by the two transducers and hence the gain of speech signalshaving these frequencies is effectively increased.

While the microphone subassembly 140 is shown in FIGS. 2A, 2B, 5, and 6as being mounted to the bottom of the mirror housing, it should be notedthat the preferred location is actually on the top of the mirrorhousing. An example of a rearview mirror assembly having a microphonesubassembly 140 a mounted on the top of the mirror housing is shown inFIGS. 7-9. Microphone subassemblies mounted on a mirror housing receivenot only direct sounds from the driver, but also sounds reflected offthe windshield. When the microphone subassembly is mounted on the bottomof the mirror housing, there is more of a time difference between thearrival of the direct sound and the reflected sound than when themicrophone subassembly is mounted on the top of the mirror housing. Whenthe arrival times are far enough apart, the resulting combinationproduces a frequency response that has a series of frequencies with nooutput. The series, when plotted, resembles a comb, and hence is oftenreferred to as the “comb effect.”

Mounting the microphone subassembly on top of the mirror housing avoidsthe comb effect in the desired pass band. As shown in the side view inFIGS. 2A and 2B, the distance between the windshield and the top of themirror housing is much smaller than that at the bottom of the mirrorhousing and thus the reflected sound adds correctly to the direct soundcreating a louder, but otherwise unaffected, version of the directsound, the end result being a higher signal-to-noise ratio and bettertonal quality. These are very important attributes in hands-freetelephony and vocal recognition in an automotive environment.

A problem with mounting the microphone subassembly to the top of themirror housing results from the fact that the microphone assembly iscloser to the windshield. When the windshield defroster is activated, asheet of air travels upward along the windshield. Thus, when themicrophone subassembly is placed on top of the mirror housing, it isexposed to more airflow as the air from the defroster passes between themirror housing and the window past the microphone subassembly. Thisairflow creates turbulence as it passes over the microphone subassembly,which creates a significant amount of white noise. To solve thisproblem, a deflector 300 extends upward from the rear of mirror housing30 a so as to smoothly deflect the airflow from the defroster overand/or beside microphone subassembly 140 a so that it does not impactthe transducers or create any turbulence as it passes over and aroundthe microphone subassembly. Because the airflow primarily would enterthe rear of the microphone subassembly, the deflector may be designed toredirect the air with minimal impact on the frequency response into thefront of the microphone subassembly. This is important for highintelligibility in the motor vehicle environment. With no direct airimpact and the avoidance of turbulence near the microphone subassembly,mounting the microphone subassembly on the top of the mirror housing canoffer superior resistance to airflow-generated noise.

As an additional measure, a signal may be transmitted over the vehiclebus or other discrete wire or wireless communication link, whichindicates that the windshield defroster has been activated. This signalcould be received and processed by the microphone processor and used tosubtract an exemplary white noise waveform that corresponds to thatdetected when the windshield defroster is activated. Alternatively, whenthe system determines that the driver is speaking into the microphoneand that the windshield defroster is activated, the system willtemporarily turn down or turn off the defroster, or otherwise produce asynthesized speech signal advising the driver to turn down thedefroster. The voice recognition circuitry within the mirror may also beutilized for purposes of recognizing noise generated by the defrostersuch that the system will be able to either advise the driver to turnthe defroster down or off or to perform that task automatically.

In addition to recognizing the sound produced by the windshielddefroster, the microphone may also be used to recognize the sources ofvarious other sounds and hence subtract them from the sound receivedwhile the driver is speaking. For example, the microphone may be used todetect low pass response to determine whether the vehicle is moving.Additionally, the microphone may be used to recognize other events, suchas a door closing or whether the air bags have been inflated. Upondetecting that the air bags have been inflated, the telematics rearviewmirror assembly may be programmed to call 9-1-1 and to transmit thevehicle location in a distress signal.

As best shown in FIGS. 7A-7D, microphone assembly 140 a is positioned onthe top of a rearview mirror assembly housing 30 a. Housing 30 aincludes a deflector 300 that extends from the upper rear portion ofhousing 30 a so as to provide a relatively flat surface 301 on which themicrophone assembly 140 a may be mounted.

Microphone assembly 140 a includes two microphone housings. A firstmicrophone housing 141 is positioned forward of a second microphonehousing 142 and is positioned closer to the face of the rearview mirrorassembly and hence closer to the driver of the vehicle. First microphonehousing 141 includes a cover 143 having a first set of ports 144 throughwhich sound may pass. Second microphone housing 142 shares a commoncover 143, which has a second set of acoustic ports 145 acousticallycoupled to second housing 142 and the transducer(s) housed therein. Bothhousings preferably include a hydrophobic windscreen to prevent ingressof moisture. The configuration of the ports on the covers and theacoustic resistivity of the windscreens may be different for each ofhousings 141 and 142 so as to compensate for any effects caused by thepositioning of the transducers on the rearview mirror assembly.

Each of microphone housings 141 and 142 preferably includes a singletransducer having its front surface facing down the approximate middleof the vehicle. As shown in FIG. 7C, the central axis of the transducersand housings 141 and 142 may be aligned along a common axis that isapproximately perpendicular to a bisector to the rearview mirrorsurface. This is to ensure the transducers are aligned to pick up thedriver's speech while not picking up too much noise on the side of thevehicle adjacent the driver, since the rearview mirror surface would beat more of an angle to allow viewing through the rear window of thevehicle. It should be noted that the transducers need not be alignedcoaxially, but may be skewed with respect to one another.

As discussed in more detail in the above-referenced '119 application,microphone assembly 140 a is preferably a second order microphoneassembly with the centers of the two transducers physically separated bybetween about 0.75 and 1.4 inches, and preferably 1.3 inches. By spacingthe transducers 1.3 inches apart, the distance between the transducersis approximately one-half the wavelength of sound at 5 kHz.

Electrical System

FIG. 11 shows the vehicle communication and control system 100 accordingto the present invention. As shown in FIG. 11, system 100 includes a GPS(or GLONAS) receiver 80 that is coupled to a microwave antenna 50 via anantenna connector 84. As discussed above, antenna 50 and GPS receiver 80are preferably mounted in mounting foot 36 of rearview mirror assembly10. GPS receiver 80 may be coupled to a local bus 102 via a cable 85,which extends between mounting foot 36 in mirror housing 30. Local bus102 interconnects the various electrical components that are preferablyprovided on the first and second printed circuit boards 110 and 112mounted within mirror housing 30. Cable 85 may also be considered as anextension of local bus 102.

Vehicle bus interface circuit 104 is preferably mounted on the sameprinted circuit board as GPS receiver 80 and is connected to local bus102 via cable 85. Vehicle bus interface 104 is then connected to thevehicle bus 106 via cable 86, which extends from mounting foot 36 to aconnector provided between the roof and headliner or within an overheadconsole. It is also possible to use an audio and data transceiver 185 inplace of bus interface 104 provided that there is a correspondingcompatible transceiver coupled to vehicle bus 106. Preferably, any suchaudio and data transceiver is a Bluetooth™ transceiver, which utilizesthe Bluetooth™ standard communication protocols.

Both map lamps 118 and switches 130 may be coupled to local bus 102.Similarly, display 45 may be coupled to a display control circuit 174which, in turn, may be coupled to local bus 102. Preferably, any maplamp(s) 118 that are provided in the assembly utilize light emittingdiodes (LEDs) so as to minimize the size of the lamp subassembliesand/or reduce the heat dissipation from the lamps. Preferably, the lampsare constructed using the white-light-emitting LEDs disclosed in any oneof: commonly assigned U.S. Pat. No. 5,803,579, commonly assigned U.S.patent application Ser. Nos. 09/148,375 and 09/426,795, or any ofcommonly assigned U.S. Patent Provisional Application Nos. 60/265,487,60/265,489, and 60/270,054.

As described further below, internal cellular telephone 170 may beprinted on circuit board 110 or 112 and connected to first RF antenna114, which is also preferably mounted on mirror housing 30. The mannerin which internal cellular telephone 170 is utilized is described infurther detail below. Antenna 114 is preferably mounted on the exteriorof mirror housing 30, however, those skilled in the art will appreciatethat this cellular telephone antenna may likewise be mounted remotelyfrom mirror assembly 10 or in mounting foot 36. By mounting antenna 114on mirror housing 30, however, the vehicle communication and controlsystem of the present invention may be confined to a single integralvehicle accessory—thereby eliminating the need for running additionalwiring to a remote location and thus saving substantial materials,manufacturing, and installation costs.

Microwave antenna 50 may also be integrated with cellular antenna 114,an RF antenna for a trainable garage door opener transmitter, an RKEreceiver, and/or an antenna for a satellite CD radio.

Rearview mirror assembly 10 may further include a moisture sensor 172that may be coupled to local bus 102. Moisture sensor 172 is alsopreferably mounted in mounting foot 36 so as to detect the presence ofmoisture such as fog, rain, dew, or snow on the vehicle windshield. Apreferred moisture sensor is disclosed in commonly assigned U.S. Pat.No. 5,923,027, the entire disclosure of which is incorporated herein byreference. As disclosed in U.S. Pat. No. 5,923,027, the output frommoisture sensor 172 may be analyzed to control the windshield wipersand/or the window and mirror defrosters of the vehicle. Because it ispreferable to mount moisture sensor 172 in mounting foot 36, moisturesensor 172 would be coupled to local bus 102 via cable 85.

System 100 may also include an imaging sensor 135 that is utilized forpurposes of controlling the vehicle headlights using headlamp controller216 (FIG. 11). Suitable sensors and headlamp controllers are disclosedin commonly assigned U.S. Pat. No. 5,837,994; U.S. patent applicationSer. No. 09/528,389 entitled IMPROVED VEHICLE LAMP CONTROLLER, filed onMar. 20, 2000; and U.S. patent application Ser. No. 09/800,460(unofficial) entitled SYSTEM FOR CONTROLLING EXTERIOR VEHICLE LIGHTS,filed on Mar. 5, 2001, by Joseph S. Stam et al., the entire disclosuresof which are incorporated herein by reference. The imaging sensorutilizes a low resolution pixel sensor to obtain an image from the frontof the vehicle to detect the presence or absence of vehicles in front ofthe vehicle for purposes of controlling the brightness of the vehicleheadlamps. The images obtained from the low resolution pixel sensor 135may also be stored in memory to provide a brief history of what was infront of the vehicle, which may be particularly advantageous whendetermining the cause of an accident. The memory in which such imagesare stored is preferably non-volatile memory unless suitable batteryback-up power is available in which case the memory may be volatilememory. During normal operation, images from sensor 135 are stored involatile memory on a first-in/first-out basis for processing to identifylight sources. Upon detection of a crash, a control circuit of thepresent invention may transfer the images stored in the volatile memoryto the non-volatile memory for subsequent retrieval. In addition to usein sensing images, sensor 135 may be used as an ambient light sensor forcontrolling an electrochromic mirror(s) 40 (FIG. 12).

As shown in FIG. 11, the vehicle communication and control system of thepresent invention may also include a speech synthesizer (or system forplayback of prerecorded messages) 176, a voice recognition circuit 178,a microphone processor 180, an audio and data transceiver 185 (usedinterchangeably throughout with “Bluetooth™ transceiver,” which is thepreferred implementation), a Bluetooth™ control circuit 188, and anaudio circuit 190. Of these components, voice recognition circuit 178,Bluetooth™ control circuit 188, and speech synthesizer 176 are coupledto a local bus 102. Speech synthesizer 176 responds to commandstransmitted over local bus 102 to generate synthesized speech signalsthat are transmitted over a line 195 to audio circuit 190. Audio circuit190 may be connected to one or more speakers 192 that are mounted insidethe rearview mirror assembly or remote therefrom so as to play back thesynthesized speech. Embodiments of the invention utilizing internalspeakers are discussed below under the heading “Internal Speakers.”Alternatively or additionally, audio circuit 190 may transmit the audiosignals via a dedicated connection 197 to the vehicle audio system so asto cause the audio system to interrupt (or superimpose upon) any radiobroadcast or other music playing over the audio system and to producethe synthesized speech. Alternatively, Bluetooth™ transceiver 185 may beused to provide an RF connection to the vehicle's audio system so as toeliminate the need for a discrete connection 195 or a connection throughthe vehicle bus.

Microphone processor 180 preferably provides two separate output audiostreams from the microphone subassembly. The first audio stream, whichis provided on line 181 to voice recognition circuit 178, is processeddifferently than a second audio stream provided on line 186 toBluetooth™ transceiver 185. The noise reduction processing performed bythe digital signal processor in microphone processor 180 renders thesounds detected by the microphones better for human listening, however,such noise reduction removes detail that is useful for voicerecognition. Thus, the second audio stream is filtered differently thanthe first audio stream since the processed signal would not be assuitable for use by the voice recognition circuit 178. Microphoneprocessor 180 preferably includes a digital signal processor (DSP).

Bluetooth™ transceiver 185 is configured to be capable of transmittingand receiving both audio signals and data signals. As illustrated,Bluetooth™ transceiver 185 is connected to second RF antenna 116. BothBluetooth™ transceiver 185 and antenna 116 are preferably mounted tomirror housing 30 as shown in FIGS. 6 and 7. It should be noted thatantennas 114 and 116 could conceivably be combined and then used forboth cellular telephone transmissions and Bluetooth™ transmissions.

As described above, Bluetooth™ transceiver 185 may receive audio signalsfrom microphones 142 and 144 via microphone processor circuit 180 overline 186. These audio signals may be modulated and transmitted viaantenna 116. Bluetooth™ transceiver 185 is also coupled to audio circuit190 and to voice recognition circuit 178 such that audio signalsreceived by Bluetooth™ antenna 116 may be played back through thevehicle audio system or a dedicated speaker 192 or otherwise transmittedto voice recognition circuit 178, which recognizes certain voicecommands and translates those commands into command signals that aretransmitted over local bus 102 and optionally over vehicle bus 106. Whendata is to be transmitted by Bluetooth™ transceiver 185 to anotherdevice, the data is first supplied to Bluetooth™ controller 188 overlocal bus 102 and then supplied to Bluetooth™ transceiver 185.

When microwave antenna 50 is tuned to receive satellite transmissionsfrom GPS satellites, microwave receiver 80 receives and supplies dataover bus 102 identifying the satellites from which transmissions arereceived, as well as a clock signal from each of the differentsatellites. In a manner well known in the art, this data may beprocessed to identify the position of the vehicle in terms of itslatitude, longitude, and altitude. Insofar as clock signals are receivedfrom the various satellites, receiver 80 also serves as a source of aclock signal that may be used to determine the time of day. Thisinformation can be used to determine the vehicle's velocity, heading andposition. Vehicle position and GPS time may be used to determine inwhich time zone the vehicle is located and thereby the local time mayalways be displayed.

If microwave antenna 50 is tuned to receive signals from one or more CDradio satellites, microwave receiver 80 serves as a source of a CDquality satellite radio broadcast transmission, which may be supplied toan audio system 234 (FIG. 11) via a discrete connection. The audio orother data may also be transmitted via an IR or low power RF link (suchas through Bluetooth™ transceiver 185). Audio could be transmitteddirectly to the vehicle's radio from the mirror assembly on a vacantchannel with a low power transmitter. This would be particularly usefulin aftermarket and retrofit applications.

As discussed above, microwave receiver 80 may be configured such thatmicrowave antenna 50 receives signals from both GPS satellites and CDradio satellites, in which case microwave receiver 80 would serve as asource of a wide variety of information and audio signals. Moreover, tothe extent that microwave receiver 80 could be tuned to receivesatellite transmissions from other communication satellites, suchinformation may be displayed on a display 45 or other displays 226 (FIG.13) connected to vehicle bus 106. Additionally, such information, ifprovided as a GPS or audio signal, may be transmitted to audio system234 as described above with respect to CD radio signals. Further still,such information may be simply used and processed by vehiclecommunication and control system 100 or otherwise transmitted by RF orIR signals to other vehicle components or non-vehicle devices viaBluetooth™ transceiver 185 or IR transmitter 134. The informationtransmitted may be derived from either the microwave receiver or vehiclebus. Information derived from the vehicle bus may be particularly usefulfor troubleshooting and diagnostic purposes. Transmission of diagnosticdata could be activated by a special vehicle startup sequence such asholding a radio or mirror button or buttons depressed while starting thevehicle. Alternatively, a command could be received via Bluetooth™transmission or other wireless communication link that would trigger thetransmission of the diagnostic data.

As shown in FIGS. 11 and 12, rearview mirror assembly 10 may alsoinclude an electrochromic mirror/compass system 120 having a connection121 to local bus 102. As shown in FIG. 12, electrochromic mirror/compasssystem 120 has a microprocessor 122 that is preferably coupled at leastto the interior electrochromic mirror 40 and optionally to externalelectrochromic mirror(s) 212, which may be coupled thereto by discreteconnection or via local bus 102 and vehicle bus 106. As will bedescribed in more detail below, microprocessor 122 may be programmed tochange the reflectivity of the electrochromic mirror(s) 40, 212 inresponse to information obtained from an ambient light sensor 126, aglare sensor 124, as well as any of the other components coupled tomicroprocessor 122 either directly or through local bus 102 or vehiclebus 106. As well known in the art, ambient light sensor 126 ispreferably mounted in a mirror housing of a rearview mirror assembly ina forward-looking location so as to be exposed to the light conditionsin front of the vehicle, whereas glare sensor 124 is typically mountedin mirror housing 30 in a rearward-facing position so as to sense glarefrom head lamps of vehicles behind the vehicle. A more detaileddescription of the manner by which microprocessor 122 may controlelectrochromic mirror(s) 120 is provided in the above-referenced U.S.Pat. No. 6,166,698. Although mirror 40 is preferably electrochromic,mirror 40 may alternatively be a simple prismatic mirror. Alternatively,mirror 40 may be replaced with a display device for providing an imagefrom a rearward facing camera.

Electrochromic mirror/compass 120 may also include a memory device 127coupled to microprocessor 122. Memory device 127 may be external tomicroprocessor 122 or internal, depending upon the need for additionalmemory. The depicted memory device 127 represents both volatile andnon-volatile memory as needed for the system.

As shown in FIGS. 6 and 12, rearview mirror assembly 10 may include aplurality of user-actuated switches 130 that provides user inputinformation to microprocessor 122. Such switches may causemicroprocessor 122 to change information displayed on display 45 or todeactivate the electrochromic mirrors 40, 212, or to initiate or answera telephone call, to name just a few functions that may be affectedthrough user actuated switches.

Display 45 may be located behind the reflective surface of the mirror ormounted adjacent the mirror in the mirror housing. Alternatively,display 45 may be mounted in front of the reflective layer and acrosspart or the entire surface of the mirror. A suitable display formounting in front of the reflective layer is an organic LED display. Anexample of such an organic LED display in a mirror is disclosed incommonly assigned U.S. patent application Ser. No. 09/311,955, theentire disclosure of which is incorporated herein by reference.

Display 45 is preferably a vacuum florescent display including at leastten seven-segmented character display areas, and preferably including atleast sixteen such character portions. Using conventional technology,such a large display requires a 42 volt power supply. However, using thetechniques disclosed in commonly assigned U.S. patent application Ser.No. 09/359,616 entitled LOW EMI MULTIPLEXED DUAL DISPLAY, filed on Jul.22, 1999, by Robert R. Turnbull, the display may be driven using a 12volt power supply and will also exhibit substantially lowerelectromagnetic interference. The entire disclosure of U.S. patentapplication Ser. No. 09/359,616 is incorporated herein by reference.

The display may provide various information including the vehicleheading, the external temperature, telephone numbers, roaminginformation, telephone and voice signal strength information, pagingmessages, control menus and selections, e-mail, navigational directions,diagnostic information, voice mail icons, traffic reports, news,weather, tire pressure warnings, blind spot warnings, stop sign/trafficlight warnings, maintenance reminders, and any other informationavailable on the Internet. Additionally, the display may be used toprovide positive feedback to the user as to which button a user hasdepressed. For example, if a user has pressed a “911” button, anindication to this effect may be displayed on display 45.

As noted above, display 45 may be mounted behind mirror 40 such that thedisplay is visible through a window provided in the reflective surfaceof mirror 40. The window may be formed by completely removing orpartially removing reflective material on the reflective surface.Alternatively, the window may be provided by forming a partiallytransmissive or partially reflective area in the reflective surface. Thewindow may also include a number of regions devoid of reflectivematerial. Creation of such devoid regions allows the display to bevisible through the reflective surface of the mirror. The devoid regionscan be created in the reflective surface through a number of techniques,such as etching (laser, chemical or otherwise), masking duringdeposition, mechanical scraping or sand-blasting. These techniques arewell known to those skilled in the art and as such are not furtherdiscussed herein. An example of an electrochromic mirror having such adisplay window is disclosed in commonly assigned U.S. Pat. No.5,825,527, by Jeffery Forgette et al., the disclosure of which isincorporated herein by reference.

Preferably, the entire reflective surface could be partially reflectiveand partially transmissive such that no “window” need be provided andthe display could be positioned anywhere behind the mirror and have anysize or configuration. Display 45 may also be comprised of a pluralityof separate displays. Examples of electrochromic mirror assemblieshaving partially transmissive reflective surfaces are disclosed incommonly assigned U.S. patent application Ser. No. 09/311,955, entitledELECTROCHROMIC REARVIEW MIRROR INCORPORATING A THIRD SURFACE METALREFLECTOR AND A DISPLAY SIGNAL LIGHT, filed on May 14, 1999, by WilliamL. Tonar et al., the entire disclosure of which is incorporated hereinby reference.

As will be explained in further detail below, vehicle communication andcontrol system 100 may include an IR transmitter 134 for transmitting anIR signal into the interior passenger area of the vehicle. This IRsignal may include any data or other information intended for portableelectronic devices that may be located in the passenger area. If suchdevices have an RF receiver, Bluetooth™ transceiver 185 may be used forthat purpose.

Vehicle communication and control system 100 may also include a receiverintended to receive RF signals or the like from remotely locatedtransmitters such as an RKE transmitter or tire pressure monitoringsensors.

As will become apparent to one skilled in the art from the descriptionof the various functions below, vehicle communication and control system100 may include various combinations of the elements identified aboveand shown in FIG. 11, and thus need not include each and every elementdescribed above. Further, although each of the elements shown in FIG. 11may be housed within rearview mirror assembly 10, some or all of thecomponents may be provided in other remote locations and transmit andreceive information over vehicle bus 106 or via RF Bluetooth™transmissions. Further, the various components that may be mounted inrearview mirror assembly 10 may be mounted in either mounting foot 36 ormirror housing 30 with appropriate electrical connections madetherebetween.

FIG. 13 shows an example of some systems and other electrical deviceswithin the vehicle that may be connected to vehicle bus 106, and hencein electrical communication with the various components that are mountedin mirror assembly 10. Specifically, the following are a few examples ofthe components that may be coupled to vehicle bus 106: navigation system210, external rearview mirrors 212, interior lights 214, head lampcontroller 216, tire pressure monitoring system 218, speedometer 220,climate control system 222, clock/display 228, engine control system230, temperature sensor 232, audio system 234, odometer 236, the vehiclewindshield wiper controller(s) and various other switches 224 and otherdisplay devices 226 that may be located throughout the vehicle.

By providing both Bluetooth™ transceiver 185 and an internal telephone170 in the vehicle communication and control system, an individualhaving a relatively low power portable cellular telephone mayeffectively utilize a higher powered cellular telephone 170 when insideor otherwise within range of the Bluetooth™ transceiver 185 in a mannersimilar to how a ZONE™ telephone operates. See, for example, U.S. Pat.No. 5,745,850. Specifically, Bluetooth™ transceiver 185 may be trainedor otherwise configured to look for signals transmitted from a person'sportable telephone and then transfer the received signals to internaltelephone 170 for transmission at a higher power. Likewise, incomingsignals may be received by internal telephone 170 and transferred to theportable telephone handset via Bluetooth™ transceiver 185. Internaltelephone 170 may be provided for emergency calls only and any cellulartelephone calls are made through the driver's portable telephone, whichin turn are transmitted through the internal telephone which transmitsat a higher power level. This is also advantageous for vehicles inEurope where use of handheld telephones in vehicles is illegal. Forexample, once a user comes within range of their vehicle, their portabletelephone is disabled and the hands-free telephone installed within themirror is activated without disruption of the telephone call. Such ahand-off from a portable telephone to internal telephone 170 may alsooccur upon detection that the vehicle alarm has been deactivated, a doorhas opened, the ignition key is inserted into the vehicle ignition, theignition is turned on, the vehicle is put into gear, the vehicle istravelling above a threshold speed, or any combination of these events.Likewise, any of these events may trigger an automatic hand-off frominternal telephone 170 to the portable telephone. For example, detectionthat the vehicle ignition has been turned off and/or opening of the doormay trigger such an automatic hand-off. Alternatively, a manuallyactivated call transfer button or voice activated command may be used tomanually cause a call transfer. Such a manual switch may be provided oneither or both of the portable telephone and internal telephone 170.

To enable such call transfer, a unique ID code associated with, andtransmitted by, one or both of the Bluetooth™ compatible transceivers ofthe portable telephone and internal telephone would be input into theother so that the respective telephone will not respond or attempt totransfer control, or partial control, of a call function to thetelephone of a third party.

While it is generally desirable to transfer the entire callfunctionality to internal telephone 170, it will be appreciated thatonly some of the call functions may be transferred. For example, it ispossible to transfer (or duplicate) the microphone and speaker functionsof the portable telephone to those of internal telephone 170. In thismanner, the transceiver, antenna, and keypad of the portable telephonewould continue to function while enabling hands-free use of the speakerand microphone of internal telephone 170 with the audio transmittedthrough a Bluetooth™ or similar communication link. As yet anotherexample, the keypad and other call initiation features(redial/speed/memory dialing) of the portable telephone may remainfunctional while the transceiver, antenna, microphone, and speakers ofinternal telephone are used.

Another possibility is that the driver or other vehicle occupant mayutilize a headset having a low power RF Bluetooth™ transceiver forcommunicating with Bluetooth™ transceiver 185 provided in rearviewmirror assembly 10. The vehicle occupant may then make cellulartelephone calls using this headset, Bluetooth™ transceiver 185, andinternal telephone 170 and may also speak into the headset microphoneand have voice commands transmitted to Bluetooth™ transceiver 185 andthen transferred to voice recognition circuit 178 where those voicecommands are translated into control signals that are transmitted overlocal bus 102 and optionally vehicle bus 106 to thereby affect variousvehicle functions.

Provided that the portable headset or portable cellular telephonecarried by a person is Bluetooth™ compatible, virtually any level ofinteraction between internal telephone 170 and the headset or portablecellular telephone is possible. For example, the cellular telephone orheadset may include a unique serial number that may be transmitted fromthe cellular telephone or headset by its Bluetooth™ transceiver. Whenthe portable cellular telephone or headset is brought within range ofBluetooth™ transceiver 185, any portion of the telephony functions maybe transferred to internal telephone 170. Conversely, a call initiatedusing the internal telephone 170 may be transferred to the portabletelephone or headset. For example, the keypad on the cellular telephonemay be used as a means for initiating a telephone call by internaltelephone 170. Additionally, the microphone and/or speaker of theportable telephone may be disabled with those functions being performedby the microphone and speaker within the vehicle while the remainder ofthe call processing and call transmission is handled by the portablecellular telephone. Further still, the portable cellular telephone couldbe used for RKE functions and/or disabling the vehicle alarm orotherwise activating the lights within or on the vehicle for illuminatedentry. This can be performed simply by having the Bluetooth™ transceiver185 continuously monitor for the presence of another Bluetooth™transceiver having the known unique identification number correspondingto the driver's cellular telephone. Also, a person may utilize theircellular telephone as a mechanism for unlocking the vehicle doors ifthey lock their keys in the car. More specifically, a person could bringtheir cellular telephone within range of Bluetooth™ transceiver 185 andeither dial in a sequence of numbers representing a door unlock code,speak into the microphone such that voice recognition circuit 178responds to a command to unlock the doors, or dial a telephone numberassociated either with the vehicle or with a service organization thatallows the person to either directly or indirectly communicate with thevehicle from a distance to either lock or unlock the vehicle doors.

Internal cellular telephone 170 is preferably a dual-band tri-modeanalog/digital telephone. Internal telephone 170 may be configured toutilize any of the standard communication protocols including AMPS, GSM,TDMA, IDEN, or CDMA. By providing internal telephone 170, the vehicleoccupants are provided with a hands-free telephone, a means forreceiving electronic mail, voice mail, Internet access, weather reports,news reports, traffic reports, and other useful information.Additionally, the vehicle occupants may use the telephone to accessconcierge services. By providing GPS receiver 80 in addition to cellulartelephone 170, a system is provided whereby an emergency 9-1-1 call mayautomatically be placed upon detection of airbag deployment oractivation of an emergency switch. Upon such activation, telephone 170dials 9-1-1 and transmits with the signal the vehicle location asdetermined by GPS receiver 80. In this way, if the vehicle occupants areunconscious, emergency vehicles may still be deployed to the identifiedlocation.

By integrating the cellular telephone, Bluetooth™ transceiver,microphone processor 180, and voice recognition circuit 178 in a commonaccessory, the system benefits from the integration by only requiring asingle digital signal processor (DSP) circuit. This clearly eliminatesthe cost of providing separate digital signal processors in thesecomponents when they are located at different locations throughout thevehicle.

Another advantage of incorporating voice recognition circuit 178 in thecontrol system is that voice recognition circuit 178 may be used toperform certain voice recognition functions that assist an automatedcall answering system having its own voice recognition functions. Suchcall answering systems are becoming more commonplace since individualsutilizing hands-free telephones often do not have easy access to akeypad to press numbers when prompted by the automated call answeringservice. Thus, these services typically request the caller to audiblyspeak one of the various options. The automated call answering systemthen performs voice recognition on the spoken option to determine how tofurther process the call. One problem facing such automated call systemsis that there is limited bandwidth through which such spoken options aretransmitted over the telephone lines. The use of cellular telephones,which may not always transmit a clear signal, creates further problems.

To improve the effectiveness of such systems, a vehicle equipped withits own voice recognition circuit 178 may allow for prerecognition of aspoken command within the vehicle. Speech synthesizer 176 may thenproduce a synthesized voice command that is transmitted to the automatedcall answering system. Provided that all speech synthesizers produce asynthesized voice that is substantially the same, the voice recognitioncircuitry in the automated call answering system may function much moreaccurately since it does not have to process a very wide variety ofspeech patterns transmitted from all of the users of the system.Further, the voice recognition circuit (178) in a vehicle may be trainedto the driver's specific voice patterns thereby providing much moreaccurate voice recognition processing. Further still, voice recognitioncircuit 178 is not limited by a restricted bandwidth when receiving thevoice commands that it must recognize.

A further option is to have voice recognition 178 recognize a spokencommand (i.e., a number, pound sign, etc.) and to have the systemtransmit additional data over the wireless telephone link data that willassist a voice recognition system within an automated call answeringsystem to recognize the spoken command. In this case, the spoken commandwould still be transmitted over the wireless telephone link in thedriver's own voice, but the additional data transmitted with the spokencommand would allow more accurate recognition by the automated voiceanswering system.

An alternative option is to employ vocal recognition in the car torecognize any spoken number, pound sign or star in the outgoingtelephone signal. Immediately after the recognition, the processor wouldadd the appropriate DTMF tone for that keypad option. At the receivingend, any voice mail system or service provider capable of DTMF tonecontrol would respond to the signal. This would allow hands-freeactivation of voice mail, remote dialing and menu optionsrequiring/desiring a keypad entry with no keypad. The driver would nothave to hear these tones, and thus, such a system would prevent thetones from distracting the driver. Another vocal command or switch couldbe used to turn this feature on and off, if necessary.

In general, the voice recognition circuit may be used to recognize anyspoken command during such time that a call is not in progress. Once acall is in progress, the voice recognition may be selectively turned offso as not to inadvertently invoke commands based upon words spokenduring the telephone conversation that are not intended to invoke suchcommands. On the other hand, when the voice recognition circuit is to beutilized to perform functions during a telephone call, a specific keyword can be utilized that is not commonly used in conversation so as toplace the system in a voice recognition mode. Such would be desirablewhen, for example, a call is placed through an automated call processingnetwork that asks for an individual to press a number on a key pad.

As shown in FIG. 11, the vehicle communication and control system mayfurther include a backup power or battery component 200. As illustrated,this circuit includes a connection 204 to the vehicle battery orignition through cable 86. Component 200 preferably includes a largecapacitor or capacitor bank 202 that stores a sufficient amount ofenergy that is received from vehicle battery/ignition so as to enablethe system to still operate for a brief period should the connection tothe vehicle battery/ignition be disrupted. A primary or rechargeablebattery may alternatively or additionally be used. The capacitor bankmay be charged to a relatively high voltage using a flyback, boost, orother switching power supply. Since E=½CV2, more energy can be storedusing a higher voltage. The stored energy can then be used to power aflyback, buck, or other switching power supply to provide regulated lowvoltage to the cellular telephone. Alternatively, a bi-directional powersupply may be used to charge and discharge the capacitor bank. Thus, forexample, if the vehicle is in an accident and the rearview mirrorassembly becomes disconnected from the vehicle ignition or battery, theinternal telephone 170 may still make the emergency 9-1-1 telephone calland transmit the vehicle location. Alternatively, internal telephone 170could initiate an emergency call and then transfer control of the callto the vehicle occupants' portable telephone if it is present andactive. This would allow the emergency call to stay active for a longerperiod of time given that portable telephones typically have arelatively long battery life. It should further be noted that internaltelephone 170 may be configured to provide less than full functions of acellular telephone and thus only be provided for purposes of emergencytelephone calls. By transmitting an emergency signal to an individual'sportable telephone and appropriately programming the portable telephone,both internal telephone 170 and the portable telephone provide aredundancy when making emergency calls that may be critical. Forexample, in the event one of the telephones is disabled in a seriousaccident, such redundancy increases the likelihood that the distresscall will be completed.

To ensure that the backup battery is fully functional in cold weatherclimates, a heater 157 is preferably utilized to heat the battery upondetection that the vehicle ignition has been turned on so as to quicklyimprove the functionality of the battery in cold weather in the eventthat an emergency or other need for the backup battery results beforethe battery may otherwise heat up as a result of the vehicle climatecontrol system.

By providing GPS receiver 80 and internal telephone 170 in the vehiclecommunication and control system, the system may be utilized to trackthe location of the vehicle. This is particularly useful when thevehicle is stolen. Upon notification that the vehicle is stolen, theowner or the police may call the vehicle and request locationinformation from GPS receiver 80. This information may then betransmitted through internal telephone 170 and utilized for the policeto locate or disable the vehicle. Also, the transmitted information mayinclude information about any accident in which the vehicle is involved.For example, this information could include the speed of the vehicleprior to the accident, whether the vehicle rolled over, whether the airbags deployed, deceleration data, and other data indicating crashdynamics and the severity of the accident. Such information can be veryhelpful in determining which emergency vehicles to dispatch to the sceneof the accident.

While integration of the components of the invention into a singleaccessory such as a rearview mirror assembly makes the system mucheasier and less costly to install, it is conceivable that a would-bethief could simply rip the rearview mirror assembly off the windshieldand throw it from the vehicle or otherwise cut any exposed cables. Onesolution to this potential problem is to provide a module within enginecontrol system 230 or within some other component connected to vehiclebus 160 or another Bluetooth™ transceiver that periodically polls acomponent located within a rearview mirror assembly to determine itspresence. Then, if the engine control system component or othercomponent remotely located from the mirror assembly determines that therearview mirror assembly has been disconnected from the vehicle bus, theengine control system executes a routine that disables the vehicle bycausing it to slowly come to a stop and prevent further movement of thevehicle. Alternatively, the vehicle would stop and refuse to restart ifthe vehicle speed dropped below a predetermined speed with the securitymirror removed. The backup power in the rearview mirror assembly couldsimultaneously be utilized to at least track the location of therearview mirror assembly and provide the police with an approximatelocation of the stolen and disabled vehicle.

Additionally, the vehicle communication and control system 100 providedin rearview mirror assembly 10 may have a particular serial number orrolling code that it transmits back to the polling engine control systemcomponent such that the engine control system component may ensure thata thief has not simply switched rearview mirrors or otherwise installedsome form of module that would fool the engine control system component.

It is also preferable that at least one component within the systemshown in FIG. 11 periodically determines the status of the othercomponents to ensure they are present and operational. If any onecomponent is disabled, the component checking the status of the othercomponents within the system may then appropriately interact with theengine control module so as to disable the vehicle in the mannerdiscussed above.

The Bluetooth™ transceiver 185 may also be utilized in connection withan RF identification tag implemented in an individual's key fob toactively sense when the RF identification tag is proximate the vehicle.When the RF identification tag comes into close proximity to the vehiclesuch that the Bluetooth™ transceiver 185 can detect transmissions fromthe RF identification tag transponder, commands may be sent viaBluetooth™ controller 188 and busses 102 and 106 to various electroniccomponents within the vehicle. For example, upon detecting the RFidentification tag for a particular individual, the system may adjustthe seats and mirrors and even the radio presets for that particularperson. Additionally, various other electronic components can bepersonalized and automatically selected for the individual identified inthe RF identification tag. For example, an individual may program thesystem to perform different and personalized functions in response toactuation of any of the switches 130. Additionally, the identificationof the person entering the vehicle may be used to select the appropriatedata in the voice recognition circuit for most effectively recognizingthe voice of that particular individual.

A transceiver located in the vehicle rearview mirror assembly may alsobe used to energize and/or receive confirmation of the presence of atransponder on the ignition key or in a key fob. In the absence of suchconfirmation, the control circuit in the rearview mirror may transmit asignal preventing starting of the vehicle. Alternatively, the vehicleengine modules may be programmed not to start the engine in the absenceof a signal from the rearview mirror indicating that the proper signalis received from the transponder on the vehicle owner's key or key fob.The transceiver in the rearview mirror may continue to interrogate thetransponder and disable the vehicle if the transponder is no longerpresent. By placing the rearview mirror in this vehicle control loop,the vehicle will not start if a thief removes the rearview mirrorassembly from the vehicle in an effort to remove the remote vehicletracking feature from the vehicle.

Additionally, Bluetooth™ transceiver 185 may be used for detectingsignals from tire pressure sensors provided in the vehicle tires. Whenthe pressure in a tire falls below a threshold level, Bluetooth™transceiver 185 may generate a warning signal that is either audioand/or visual.

Bluetooth™ transceiver 185 may also be used to receive RKE RF signalsand respond by unlocking vehicle doors and disarming a security system.Further, Bluetooth™ transceiver 185 may be used to transmit garage dooropening signals and other control signals to various receivers in aperson's home, security gate, or other building.

The Bluetooth™ transceiver 185 may also be used to transmit diagnosticinformation to the user and out of the car.

Another use for the Bluetooth™ transceiver is to detect whether or notthere is a similarly equipped vehicle in the vehicle's blindspot.Specifically, when a driver activates the turn signal, Bluetooth™transceiver 185 receives a command via busses 106, 102, and Bluetooth™controller 188 and responds by transmitting a signal indicating that aturn is about to be completed in a particular direction. The adjacentvehicle may then receive the signal and generate a warning signal orotherwise respond back to the vehicle with its turn signal on so as towarn the driver of the turning vehicle that there is a vehicle in itsblindspot. Additionally, Bluetooth™ transceiver 185 may receive signalsfrom stop signs or traffic lights indicating their presence or theirparticular status so as to warn the driver in advance. As shown in FIG.7A, a number of colored indicator lights 159 may be provided on therearview mirror assembly to display the status of the traffic lights.Specifically, a first indicator light 159 a may be a red light, a secondindicator light 159 b may be a yellow light, and a third indicator light159 c may be a green indicator light. This will enable drivers to merelylook at the rearview mirror to see the status of a traffic light in suchcircumstances where the sun is in their eyes or their view of thetraffic light is otherwise impeded by the vehicle roof or otherobstacle.

Further still, Bluetooth™ transceiver 185 may be utilized to transmitand receive information for payment of tolls at toll booths or paymentof various expenses by transmitting a credit card number or debit cardnumber and passcode to an external receiver.

By providing sufficient memory in system 100, the system may be utilizedas a data/accident recorder or black box. The black box may storeinformation such as the speed the vehicle was traveling prior to acrash. Other accident reconstruction information can also be stored suchas readings from gyroscopes, suspension systems, air bag deploymentsensors, roll sensors, GPS data, and other devices or sensors thatindicate dynamics of a crash. The memory may also store a history of thespeed, direction, driver input, ambient temperature, and otherinformation available on the vehicle bus or other interface, such thatthis information may be read from memory to prove that the vehicle wastraveling at a specific speed to either serve as additional evidencethat a speeding ticket was or was not warranted.

Electronic vehicle compass systems are known that include electroniccompass sensors for sensing the earth's magnetic field, and generate anelectrical signal representing the vehicle's direction of travel basedupon the sensed magnetic field. Such systems are typically calibratedbased upon sensor readings obtained while driving the vehicle throughone or two closed loops. Such calibration techniques are also well knownand described in U.S. Pat. No. 5,761,094. These known electronic compasssystems compensate the compass sensor readings based upon thecalibration data as well as other filtering parameters, and display thecurrent vehicle heading on a display device commonly provided in theoverhead console or interior rearview mirror of the vehicle. One ofthese parameters is used to adjust the vehicle heading based upon ageographical zone of variance in which the vehicle is currently located.Typically, a user is required to manually input in which zone thevehicle is currently located. U.S. Pat. No. 5,761,094, however, utilizesvehicle position data obtained from a GPS receiver to determine thevehicle's current location and to determine which zone of variance thecompass system should use to further compensate the sensed vehicleheading.

As noted above, the prior art electronic compass systems all utilizesome form of device that senses the earth's magnetic field. Such sensingdevices are relatively expensive and must be mounted in particularlocations within the vehicle so that the sensors are not adverselyaffected by the metal structure of the vehicle, which may introduceerrors to the magnetic sensors. Such magnetic sensors are alsosusceptible to errors resulting from driving over railroad tracks anddriving in large cities. Further, the compasses must be calibrated foreach different model vehicle in which it is mounted, since the bodystyle of these different model vehicles may have differing effects onthe way in which the compass sensors sense the earth's magnetic fieldand sense the vehicle's current heading.

The compass system according to the present invention overcomes theproblems noted above with respect to conventional electronic compasssystems. According to one aspect of the present invention, the compasssystem includes an electronic compass sensor for sensing the earth'smagnetic field and for generating an electrical signal representing thevehicle's direction of travel based upon the sensed magnetic field, amicrowave receiver for receiving transmissions from satellites of aposition identification system constellation and for generating vehicleposition data from the satellite transmissions, a control circuitcoupled to the electronic compass sensor and to the microwave receiverfor determining the vehicle's direction of travel from the vehicleposition data received from the microwave receiver, adjusting thevehicle's direction of travel as identified by the electronic compasssensor using calibration data, comparing the vehicle's direction oftravel as determined using the vehicle position data with the vehicle'sdirection of travel as received from the electronic compass, andrecalibrating the compass system when the vehicle's direction of travelas determined by both the microwave receiver and the adjusted electroniccompass sensor readings are not substantially the same. The compasssystem further includes a vehicle direction indicator, such as display45, coupled to the control circuit for advising a vehicle occupant ofthe vehicle's direction of travel.

If combined with a magnetic sensor, the GPS heading data may be used toprovide continuous calibration correction for the magnetic sensor,allowing placement of the magnetic sensor in a non-fixed location, suchas inside the movable portion of the rearview mirror assembly. Magnetic,angle rate, speedometer, odometer, or other inertial sensor data canthen be used to supplement GPS data when buildings or otherenvironmental obstacles interfere with reception of the GPS satelliteconstellation.

According to yet another aspect of the present invention, the inventivecompass system does not include an electronic compass sensor or anyother form of sensor that senses the earth's magnetic field, but insteadutilizes vehicle position data that is derived from transmissionsreceived from satellites of a position identification systemconstellation utilizing a microwave receiver that is mounted in thevehicle. By utilizing the vehicle position data that is available frommicrowave receiver 115, a control circuit including microprocessor 110may use this data to directly determine the vehicle's current heading,which is subsequently displayed on display device 45.

Because it is possible that tunnels or tall buildings may at times blockthe signals from some of the satellites that are otherwise needed toaccurately determine the vehicle heading, the present inventionpreferably utilizes information obtained from the vehicle speedometerand a gyroscope, wheel speed sensors, or the like to compute the headingusing dead reckoning. The heading computed using dead reckoning may thenbe compared with that obtained from the GPS receiver to more accuratelydetermine the actual vehicle heading. For example, if the GPS unit isindicating a change in heading but the gyroscope has not detected thatthe vehicle has turned, the compass processor may determine that thedisplayed heading should not change. Alternatively, the processor mayuse the dead reckoning heading as a filter mechanism for the headingobtained from the GPS unit. For example, if the heading obtained by theGPS unit changes and the gyroscope has indicated that no change indirection has occurred, the compass processor may maintain the presentlydisplayed heading for a predetermined time period at which point theprocessor will either change the heading to correspond to that obtainedfrom the GPS unit or will maintain the heading if the heading obtainedfrom the GPS unit fluctuates back and forth during this time period.Thus, dead reckoning may be utilized not only when the GPS unitdetermines that there is an insufficient number of satellite signalsreceived, but may be used at all times to improve the accuracy of thevehicle heading that is displayed or otherwise communicated to thedriver.

Thus, the inventive electronic compass system may be constructed withoututilizing an electronic compass sensor, and may therefore provideaccurate vehicle heading information independent of the earth's magneticfield and its inherent anomalies when sensed by a sensitive electroniccompass sensor. Accordingly, much of the expense of providing suchmagnetic field sensors may be eliminated.

The GPS unit may compute the vehicle location and heading autonomouslyor the vehicle location and heading may be computed with the aid of anetwork. This network-aided navigation techniques distributes theprocessing demands necessary to compute the vehicle location and headingto other processors either within the vehicle or external to thevehicle. For example, the GPS receiver in the vehicle may be used tocollect information from the satellites and then transmit thisinformation via internal telephone 170 to a base station which performsthe computations and transmits the heading and/or vehicle location backto the vehicle. Such a system allows for the use of less-expensiveprocessing circuits in the vehicle's system. Similarly, the processingpower demands could be performed by another processor located elsewherein the vehicle. The communication of the information obtained from theGPS receiver may be transmitted to that other processor either over thevehicle bus or via a discrete wire or wireless link. For example, theinformation could be transmitted by means of Bluetooth™ transceiver 185or another RF or IR link. Yet another alternative is that the processingof this information could be performed by the driver's portable computeror personal digital assistant and such information could be transmittedto that device by means of a Bluetooth™ transceiver or IR link.

One benefit of having much of the vehicle location and headingprocessing performed by a base station is that the base station mayprovide a clock signal that is received from GPS satellites and that hasan accuracy approaching that of an atomic clock. Such a base stationwould require less satellite signals to be received by the vehicle toaccurately compute the vehicle heading. Additionally, the system couldbe programmed to only communicate with a base station when it determinesthat it does not have sufficient satellite signals to accurately computethe vehicle heading or location. Another benefit to such sharedprocessing with a base station is that the base station may alsotransmit other data with the vehicle location/heading. Such informationmay include traffic or construction information along with recommendeddetours.

Another feature enabled by the present invention is a navigation system.The navigation system may provide visual information to the driver on adisplay or audible driving instructions that are downloaded into memoryand communicated to the driver using speech synthesizer 176 or audioplayback/decompression system (i.e., mp3, wav, or other audio format).Such direction information could be presented to the driver at each legof a given trip based upon the determined location of the vehicle as itapproaches an upcoming turn or exit. While there are many navigationalsystems disclosed in the prior art that utilize data from a GPS unit,many of these systems require vast amounts of map data to be storedwithin the vehicle. Furthermore, when such vast amounts of informationare stored in the vehicle, the information may quickly become out ofdate and not provide information such as information pertaining toconstruction or traffic congestion. In addition, a large and expensivenon-volatile memory would need to be utilized in the vehicle to storeall of this information. According to one aspect of the presentinvention, an Internet web site may be provided that contains accurateand up-to-date information including any map data, directional data,points of interest, traffic congestion information, and constructioninformation. A driver may access such a web site and provide theirorigination and destination locations so as to download only informationpertaining to that particular trip into either a portable storage mediumor into memory within the vehicle via an RF or IR wireless link.Alternatively, this information could be downloaded into the vehicle viathe internal telephone provided in the vehicle. Such information mayinclude visual map data limited to that along the route to be traveled.The information could also include audible and/or visual prompts thatare played back by speech synthesizer 176 over the vehicle audio systemor an internal speaker or displayed by the mirror display. Theinformation may further include points of interest such as gas stations,restaurants, and lodging facilities.

The microphone and voice recognition portions of the system may beutilized by the driver to input inquiries such as “identify closest gasstation.” The system may then access the downloaded information andeither display the location of the closest gas station on the mapdisplay and/or play back a synthesized audible message identifying thelocation of the gas station and giving directions.

The advantage of such a system is that it does not require excessiveamounts of memory to be provided in the vehicle and the information thatis stored in the vehicle is much more current than in prior systems.

Another way in which the information may be requested and downloadedwould be through requests entered by the driver within the vehicle byway of a cellular telephone call from internal telephone 170 to aservice center. The service center may have, for example, voicerecognition capabilities such that the driver may simply state thedesired destination into the microphone of the vehicle such that thedestination information may be sent to the automated call service centeralong with GPS information identifying the current location of thevehicle. The information may then be translated by the automated callcenter into route information that is subsequently transmitted back tothe vehicle's navigation system.

Various features of the telematics rearview mirror assembly describedabove may be enabled or disabled depending upon the status of thevehicle. For example, when the vehicle ignition is off, the system maybe utilized to receive RKE signals. When the vehicle ignition is on, thesystem need not receive RKE signals. Similarly, the cellular telephonemay be disabled when the vehicle doors are locked and the alarm isactivated. Moreover, the telephone may further be activated if thevehicle's transmission is in drive or if the vehicle is travelling at aspeed exceeding a threshold level.

Additionally, the telephone within the rearview mirror may be disabledwhen a key is not in the vehicle ignition except, perhaps, for enablinga call to be made to 911 for emergency purposes. Such disabling wouldpossibly prohibit unauthorized calls by someone breaking into thevehicle.

Features within the above-described telematics mirror may also beenabled, disabled, or modified based upon location information derivedfrom the in-vehicle GPS and navigation systems. More specifically, thenavigation system may include a database of local regulations and, basedupon the location of the vehicle as derived from the GPS system, thesystem may enable or disable certain features of the vehicle and/ortelematics system. For example, in some locations, local ordinancesdictate that only hands-free telephones may be operated in a vehicle,whereas in other locations, telephones may have been completely bannedfrom use. In still other locations, telephones may be used only ashands-free telephones when the vehicle is in motion. All of thesefeatures could be effectively enabled or disabled based upon input fromthe GPS system, navigation system, and from the vehicle statusinformation (i.e., vehicle speed or transmission information).Additional features that may be enabled or disabled that may be includedin the rearview mirror assembly include a speed limit warning and/orengine governor that determines the speed limit for the road on whichthe vehicle is traveling based upon the GPS location signal andnavigation database, and generates a warning if the speed of the vehicleexceeds the speed limit or a reasonable threshold above or below thespeed limits. The system could also be used to govern the vehicle'sengine so as to prevent a person from exceeding the speed limit or areasonable range above the speed limit. Similarly, a radar detector inthe vehicle may be selectively enabled or disabled based upon the GPSlocation signal and data obtained from the navigation database as towhether or not radar detectors are permitted in the location in whichthe vehicle is being driven.

Another feature that may be included in a rearview mirror assembly is arain/fog sensor. The rain/fog sensor may generate a control signal toturn on or off the vehicle windshield wipers based upon a detection ofmoisture on the vehicle windshield. The connection to the vehiclewindshield wipers may be utilized to disable the windshield wipers insituations where the GPS system does not detect any GPS satellites inthe sky. When GPS satellites are not detected in the sky, this couldserve as an indication that the vehicle is inside of a car wash, inwhich case it would be desirable to disable entirely the ability of theoperator of the vehicle to activate the windshield wipers. Whenwindshield wipers are activated in a car wash, there is a significantpossibility that the windshield wipers could be ripped off the vehicleby the car wash brushes. In general, operators of the car washes pay forsuch damage caused to a vehicle. Further, the time and effort requiredto have the windshield wipers replaced creates an additional burden onthe owner of the vehicle. Thus, there is a need for a system thatdisables the windshield wipers of a vehicle upon entry into a car wash.Another mechanism that could be used to disable the windshield wipers isto provide a transmitter that transmits a predetermined RF controlsignal, at the entry to each car wash. The telematics rearview mirror ofthe present invention could be used to sense the RF control signaltransmitted from such a transmitter and respond by disabling thevehicle's windshield wipers. Additionally, the system could respond bylowering the vehicle's radio antenna (if the vehicle includes such anautomatic antenna), and also to roll up and lock the vehicle windows andto close a sunroof, if present.

In addition to the functions above, any of the functions disclosed inU.S. Pat. No. 6,166,698 may also be performed by the inventive vehiclecommunication and control system.

FIG. 14 graphically illustrates currently acceptable EMI levels for bothnarrowband and broadband emissions for a rearview mirror assembly. Inthis context, broadband refers to a bandwidth which is greater than thatof the receiver that is used to measure emissions. Conversely,narrowband refers to a bandwidth that is less than that of the receiverthat is used to measure emissions. A typical EMI measurement receiverhas a bandwidth of approximately 10 kHz. A typical broadband emissionsource includes ignition systems and brush type DC motors. A typicalnarrowband emission source includes microprocessors, clocks, pulse widthmodulated motor drivers and light dimmers and chopping type powersupplies.

As illustrated in FIG. 14, from 0.4-20 MHz, narrowband emissions arelimited to 28 dBμV/m and broadband emissions are limited to 61 dBμV/m,more preferably to 51 dBμV/m, and most preferably 41 dBμV/m. From20-75.167 MHz, narrowband emissions should not exceed 15 dBμV/m and thebroadband emissions should not exceed 28 dBμV/m. From 75.167-119.132MHz, narrowband emissions are limited to 15 dBμV/m and broadbandemissions are limited to 38 dBμV/m. From 119.132-375 MHz, narrowbandemissions should not exceed 15 dBμV/m and broadband emissions should notexceed 28 dBμV/m. In the range of 375-1000 MHz, narrowband and broadbandlimitations are approximately linear.

At 375 MHz, narrowband emissions should not exceed 25 dBμV/m and at 1000MHz narrowband emissions should not exceed 34.8 dBμV/m. At 375 MHz,broadband emissions should not exceed 38 dBμV/m and at 1000 MHzbroadband emissions should not exceed 47.8 dBμV/m. Of particularinterest in this case is the frequency range from 0.4-20 MHz. Aspreviously stated, in this frequency range narrowband emissions shouldbe less than about 28 dBμV/m and broadband emissions should be less thanabout 41 dBμV/m.

FIG. 15 illustrates a typical narrowband emission spectrum. Theillustrated narrowband emission spectrum is within the narrowbandemission limits of FIG. 14. As stated above, a typical narrowbandemission source includes microprocessors, clocks, pulse width modulatedmotor drivers and light dimmers and chopping type power supplies. Thenarrowband emission spectrum of FIG. 13 is provided for illustrationonly and is not intended to be limiting. One skilled in the art willappreciate that narrowband emission spectrums depend on thecharacteristics of a given circuit or device.

FIG. 16 graphically depicts a typical broadband emission spectrum. Thebroadband emission spectrum, of FIG. 16, is within the broadbandemission limits as set forth in FIG. 14. As previously stated, a typicalbroadband emission source includes ignition systems and brush type DCmotors. The illustrated broadband emission spectrum is only provided asan example and is not intended to be limiting. One skilled in the artwill appreciate that broadband emission spectrums also depend on thecharacteristics of a given circuit or device.

To obtain a rearview mirror assembly meeting the above EMI criteria, thecircuitry disclosed in commonly assigned U.S. patent application Ser.No. 09/359,616, filed on Jul. 22, 1999 is preferably utilized. Theentire disclosure of U.S. patent application Ser. No. 09/359,616 isincorporated herein by reference. A way to further ensure that theabove-described rearview mirror assembly meets the EMI requirements isto encase one or more of printed circuit boards 110 and 112 in a metalcase such as a copper case, or a plastic case or mirror housing coatedwith a conductive/resistive coating such as a vacuum metallized coatingor a copper-silver-loaded paint. Preferably, the circuit elements thatrequire such shielding are provided on only one of the two circuitboards such that only one of the circuit boards need be encased since itis preferred that the antennas not be so encased.

Other techniques for ensuring that the above-described rearview mirrorassembly meets the EMI requirements is to utilize time multiplexing.This may be accomplished by utilizing a jittered clock source, orotherwise managing which tasks are performed within the mirror at anygiven instant. For example, when an RF receiver within the mirrorhousing is actively receiving an RF signal, one or more of the otherfunctions within the mirror may be temporarily disabled. Given the shortduration intervals at which an RF signal may be received, suspendingother functions may be accomplished with little disruption. In general,the EMI levels of a rearview mirror assembly may be measured for eachseparate function it performs and for various combinations of thefunctions to determine which functions may be enabled simultaneously,and which functions may not be enabled when other functions are beingperformed. Priorities for these functions would also need to beestablished.

In some implementations of the inventive telematics system, it may benecessary to utilize two different power supplies to generate differentvoltages for the various components of the circuit. For example, thedisplay may require a twelve-volt supply and various processors withinthe circuit may require five volts. These power supplies may be switchedpower supplies, which operate at different frequencies. The frequency atwhich one power supply may operate may be a multiple of the frequency atwhich another power supply operates. To reduce the EMI levels producedby the switched power supplies, it may be desirable to synchronize theseswitched power supplies so as to not produce sum and difference signalsfrom the resultant EMI that is generated by these supplies. Byeliminating the sum and difference signals, those frequency componentsare not present in the EMI and it is easier to focus efforts oneliminating the EMI generated at the particular frequency components atwhich the switched power supplies operate.

Internal Speakers

While the use of the vehicle's existing audio system is the preferredway to play back audio from a rearview mirror incorporating thetelematics components of the present invention, some vehicle radios donot include an audio input jack that would enable remote use of thespeakers. Further, even in vehicles that come with a standard radiohaving an input jack, there is the possibility that the vehicle ownermay replace the radio with an after-market radio that does not includesuch an input jack. For these reasons, it may be desirable toincorporate and utilize internal speakers within the rearview mirrorassembly.

Providing speakers in a rearview mirror presents several challenges.First, the speakers have to be very small and yet create an output loudenough to be clearly heard over the typical background noise present ina vehicle. Second, the microphone, if exposed to the required loudspeaker output, will become overloaded. Even through the use ofswitching to shut off either the speaker or the microphone, thisoverloading can cause problems. Switching, though common in hands-freetelephones, is generally undesirable and can be avoided provided thatthe speaker sound is not loud relative to the driver's speech level atthe microphone.

In accordance with one aspect of this invention, the above-notedmicrophone overload problem may be ameliorated by positioning a speakerat one end of the rearview mirror housing and providing an acousticallycoupled port at the opposite end of the rearview mirror assembly. Anexample of such a rearview mirror is shown in FIG. 17. As shown, aspeaker 500 is positioned on the forward-facing surface of the rearviewmirror housing 502 (the “forward-facing surface” is that which facestoward the windshield and opposite that which faces the driver). Thespeaker is positioned so as to generate sound toward the vehiclewindshield such that the higher frequency sound is reflected towards thedriver's ears. In this regard, louvers 504 may be disposed as a grillfor speaker 500 to direct the sound in a desired direction. Louvers 504also serve to protect speaker 500 from damage. The rearview mirrorhousing 502 further includes an acoustic port 506 disposed on anopposite end from speaker 500. Port 506 also preferably opens towardsthe windshield so as to project sound towards the windshield such thatit may be reflected towards the driver's ears and away from microphone508. Preferably, microphone 508 is mounted midway on or within rearviewmirror housing 502 between speaker 500 and acoustic port 506. Becausethe sound exiting acoustic port 506 is 180 degrees out of phase with thesound generated from speaker 500, the sound levels to which microphone508 is exposed would be nulled at certain lower wavelengths.

An alternative internal speaker construction is shown in FIG. 18. Inthis assembly, a second speaker 510 having louvers 512 is utilized inplace of acoustic port 506. By utilizing two speakers, the acousticpower may be effectively doubled. The use of two speakers also allowsfor smaller speakers to be utilized than would otherwise be utilized ifonly one speaker was used. By using two speakers at each end of mirrorhousing 502 facing towards the windshield, a dipole may be created.Speakers 500 and 510 are preferably driven out of phase such that soundon the left side of the microphone is out of phase with the sound on theright side. In the center, where microphone 508 is disposed, there wouldbe a null so that the effect of providing the internal speakers would beminimized.

Dipolar output is very efficient around 1 kHz, since half-wave spacingis possible. Assuming a deep null over the microphone is desirable,active null adjustment may be achieved. The two speaker outputs may beadjusted on a band by band basis to minimize the speaker-generated soundsensed by microphone 508.

Speakers 500 and 510 may be directly driven by two electrical signalsthat are out of phase. Alternatively, the two speakers may be connectedvia an acoustically inductive duct. A resonant frequency would be chosento support lower frequency efficiency. The inductance of the duct woulddecouple the cavities at higher frequencies. One advantage to utilizingdirect electrical drive of the speakers is that the extent to which thespeakers are driven out of phase may be dynamically adjusted in responseto the signal obtained from the microphone. In this manner, thefrequency band that is nulled may be adjusted. Such adjustment may bedesirable due to the fact that the mirror may be tilted in relation tothe windshield and may differ from one vehicle to another.

An additional advantage of utilizing two speakers is the redundancy thatis provided such that the failure of one of the speakers would not stopoutput, but only eliminate the benefits of utilizing two separatespeakers.

An added benefit of providing internal speakers in a rearview mirrorassembly is that the speakers may also be used for generating sound fromthe vehicle's audio system. For example, such speakers could be used fora central or mono channel output from the vehicle's radio. Such a centerchannel is desirable in light of the implementation of variousmulti-media equipment, such as televisions and VCRs, in a vehicle.

Speakers 500 and 510 are preferably lightweight piezo electric speakersso that they would not interfere with a magnetic compass that may belocated within the rearview mirror assembly or otherwise locatedproximate the rearview mirror assembly. The speakers are preferablydriven using a class D amplifier.

While the internal speakers have been described as being positioned inthe rearview mirror housing, at least one speaker may be located in ahousing mounted to the foot of the rearview mirror assembly. Forexample, a speaker could be mounted in antenna housing 54.

If use of the vehicle audio system is possible without providing addedspeakers, it may be desirable to provide audio input signals to thevehicle's radio where the audio signal for the left channel is invertedrelative to that of the right channel. In this manner, a null may becreated near the center of the vehicle where the microphone is mountedon the rearview mirror assembly. This would generally create a null atlow frequencies where acoustic feedback is generally the worst.

Additionally, if a microphone and speaker are to be mounted in aproximity to one another in the same or different housings of one ormore vehicle component, such as a visor, overhead console, A-pillar,instrument panel, etc., similar techniques to those employed in arearview mirror may be utilized. For example, if a microphone andspeaker are both mounted in a sun visor, a second speaker or port may beprovided such that the microphone lies between the first speaker andeither a second speaker or port, which provides an out-of phase signalto create a null at the microphone.

The above description is considered that of the preferred embodimentsonly. Modifications of the invention will occur to those skilled in theart and to those who make or use the invention. Therefore, it isunderstood that the embodiments shown in the drawings and describedabove are merely for illustrative purposes and not intended to limit thescope of the invention.

1. A rearview assembly for a vehicle comprising: a mirror mountingstructure including a mirror housing and adapted to be mounted to thevehicle; electronic circuitry contained in said mirror housing; anantenna for a wireless telephone mounted to said mirror mountingstructure; and an electromagnetic shield provided between saidelectronic circuitry and said antenna to substantially blockelectromagnetic radiation generated by said electronic circuitry fromreaching said antenna.
 2. The rearview mirror assembly of claim 1,wherein said antenna is mounted to said mirror housing.
 3. The rearviewmirror assembly of claim 1, wherein said electromagnetic shield iselectrically coupled to a ground of said antenna to function as a groundplane.
 4. The rearview mirror assembly of claim 1, wherein saidelectromagnetic shield includes a conductive coating on an insidesurface of said mirror housing.
 5. The rearview mirror assembly of claim4, wherein said mirror housing includes an aperture extending from anoutside surface of said housing to the inside of said housing andthrough said conductive coating, said antenna is part of an antennastructure that is mounted to said mirror housing, and a portion of saidantenna structure extends through said aperture.
 6. The rearview mirrorassembly of claim 5, wherein at least one electrical lead from saidantenna extends through said aperture.
 7. The rearview mirror assemblyof claim 1, wherein said electronic circuitry is disposed between twocircuit boards, and wherein said electromagnetic shield includes ashielding gasket disposed between the two circuit boards and surroundingsaid electronic circuitry.
 8. The rearview mirror assembly of claim 1,wherein said mirror housing exhibits an electromagnetic interferencelevel less than about 41 dBμV/m for emissions in the frequency rangefrom about 0.4 MHz to about 20 MHz.